{"title":"First Alert Carbon Monoxide Alarms \u0026 Detectors","description":"\u003c!-- category-description-first-alert-carbon-monoxide-alarms-detectors.html --\u003e\n\u003c!-- Collection: \/collections\/first-alert-carbon-monoxide-alarms-detectors --\u003e\n\u003c!-- Push to: custom_collections body_html via Admin API --\u003e\n\n\u003ch2 style=\"color:#e0e0e0;margin-bottom:8px;\"\u003eThree Decisions. Nine Models. One First Alert CO Alarm for Every Home.\u003c\/h2\u003e\n\u003cp style=\"color:#b0bec5;font-size:0.9em;margin-top:0;\"\u003eUL 2034 | Electrochemical Sensor | 85 dB | Battery, Plug-In, and Combination Options\u003c\/p\u003e\n\n\u003cp style=\"color:#e0e0e0;\"\u003eThe \u003cstrong\u003e\u003ca href=\"\/products\/first-alert-co410-battery-carbon-monoxide-alarm-with-digital-ppm-display-and-peak-memory\" style=\"color:#4fc3f7;\"\u003eFirst Alert CO710\u003c\/a\u003e\u003c\/strong\u003e is the best CO alarm in this collection for most households — a sealed 10-year lithium battery that never needs replacing, a digital display showing real-time PPM and room temperature, and a 10-year warranty that matches the alarm's full service life. If budget is the constraint, the \u003cstrong\u003e\u003ca href=\"\/products\/first-alert-co250-battery-carbon-monoxide-alarm-with-tamper-resistant-cover\" style=\"color:#4fc3f7;\"\u003eCO606\u003c\/a\u003e\u003c\/strong\u003e delivers reliable plug-in CO protection with 9V battery backup for under $25. Three decisions determine which of these nine models belongs in your home: \u003cstrong\u003epower source\u003c\/strong\u003e (battery vs. plug-in), \u003cstrong\u003edisplay and diagnostics\u003c\/strong\u003e (audible-only vs. real-time PPM readout), and \u003cstrong\u003especial scenarios\u003c\/strong\u003e (multi-room interconnect, gas appliances, or rental properties). All nine models are UL 2034 listed; one exception applies — see the CO600 note below.\u003c\/p\u003e\n\n\u003ch3 style=\"color:#ffb74d;margin:28px 0 10px;\"\u003eQuick Picks — All 9 First Alert CO Alarm Models at a Glance\u003c\/h3\u003e\n\n\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;color:#e0e0e0;margin:0 0 8px;font-size:0.88em;\"\u003e\n\u003cthead\u003e\n\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"padding:9px 10px;border:1px solid #333;color:#ffb74d;text-align:left;\"\u003eModel\u003c\/th\u003e\n\u003cth style=\"padding:9px 10px;border:1px solid #333;color:#ffb74d;text-align:left;\"\u003eBest For\u003c\/th\u003e\n\u003cth style=\"padding:9px 10px;border:1px solid #333;color:#ffb74d;text-align:center;\"\u003ePower\u003c\/th\u003e\n\u003cth style=\"padding:9px 10px;border:1px solid #333;color:#ffb74d;text-align:center;\"\u003eDisplay\u003c\/th\u003e\n\u003cth style=\"padding:9px 10px;border:1px solid #333;color:#ffb74d;text-align:center;\"\u003ePrice\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr style=\"background:#1e2a1e;\"\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;font-weight:700;\"\u003e\u003ca href=\"\/products\/first-alert-co410-battery-carbon-monoxide-alarm-with-digital-ppm-display-and-peak-memory\" style=\"color:#4fc3f7;\"\u003eCO710\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;color:#ff9800;font-weight:700;\"\u003e⭐ Best Overall\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;text-align:center;\"\u003eSealed 10-yr battery\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;text-align:center;\"\u003ePPM + temp\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;text-align:center;\"\u003e$38.99\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;font-weight:700;\"\u003e\u003ca href=\"\/products\/first-alert-co410-battery-carbon-monoxide-alarm-with-digital-ppm-display-and-peak-memory\" style=\"color:#4fc3f7;\"\u003eCO615\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;color:#ff9800;font-weight:700;\"\u003e🔌 Best Plug-In\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;text-align:center;\"\u003eAC + AA backup\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;text-align:center;\"\u003ePPM (backlit)\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;text-align:center;\"\u003e$35.88\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#222;\"\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;font-weight:700;\"\u003e\u003ca href=\"\/products\/first-alert-co250-battery-carbon-monoxide-alarm-with-tamper-resistant-cover\" style=\"color:#4fc3f7;\"\u003eCO511\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;color:#ff9800;font-weight:700;\"\u003e📡 Best Multi-Room\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;text-align:center;\"\u003eAA battery\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;text-align:center;\"\u003eNone (voice alert)\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;text-align:center;\"\u003e$52.64\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;font-weight:700;\"\u003e\u003ca href=\"\/products\/first-alert-co410-battery-carbon-monoxide-alarm-with-digital-ppm-display-and-peak-memory\" style=\"color:#4fc3f7;\"\u003eCO410\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;color:#ff9800;font-weight:700;\"\u003e🔬 Best Diagnostic\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;text-align:center;\"\u003eAA battery\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;text-align:center;\"\u003ePPM + peak memory\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;text-align:center;\"\u003e$34.98\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#222;\"\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;font-weight:700;\"\u003e\u003ca href=\"\/products\/first-alert-co250-battery-carbon-monoxide-alarm-with-tamper-resistant-cover\" style=\"color:#4fc3f7;\"\u003eGCO1\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;color:#ff9800;font-weight:700;\"\u003e🔥 Best for Gas Homes\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;text-align:center;\"\u003eAC + 9V backup\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;text-align:center;\"\u003eCO PPM\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;text-align:center;\"\u003e$50.45\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;font-weight:700;\"\u003e\u003ca href=\"\/products\/first-alert-co250-battery-carbon-monoxide-alarm-with-tamper-resistant-cover\" style=\"color:#4fc3f7;\"\u003eCO606\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;color:#ff9800;font-weight:700;\"\u003e💰 Best Budget Plug-In\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;text-align:center;\"\u003eAC + 9V backup\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;text-align:center;\"\u003eNone\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;text-align:center;\"\u003e$23.99\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#222;\"\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;font-weight:700;\"\u003e\u003ca href=\"\/products\/first-alert-co250-battery-carbon-monoxide-alarm-with-tamper-resistant-cover\" style=\"color:#4fc3f7;\"\u003eCO250\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;\"\u003eBest for Rentals\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;text-align:center;\"\u003e9V battery\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;text-align:center;\"\u003eNone (tamper-resist.)\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;text-align:center;\"\u003e$23.25\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;font-weight:700;\"\u003e\u003ca href=\"\/products\/first-alert-co250-battery-carbon-monoxide-alarm-with-tamper-resistant-cover\" style=\"color:#4fc3f7;\"\u003eCO400\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;\"\u003eBest Budget Battery\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;text-align:center;\"\u003e9V battery\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;text-align:center;\"\u003eNone\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;text-align:center;\"\u003e$22.49\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#222;\"\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;font-weight:700;\"\u003e\u003ca href=\"\/products\/first-alert-co250-battery-carbon-monoxide-alarm-with-tamper-resistant-cover\" style=\"color:#4fc3f7;\"\u003eCO600\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;color:#ef5350;\"\u003e⚠️ Commercial Only\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;text-align:center;color:#ef5350;\"\u003eAC only — no backup\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;text-align:center;\"\u003eNone\u003c\/td\u003e\n\u003ctd style=\"padding:8px 10px;border:1px solid #333;text-align:center;\"\u003e$29.98\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp style=\"color:#9e9e9e;font-size:0.82em;margin-top:4px;\"\u003e\u003cem\u003eAll nine models: UL 2034 listed | Electrochemical CO sensor | 85 dB alarm. CO600 exception: AC-only, no battery backup — not recommended for residential use.\u003c\/em\u003e\u003c\/p\u003e\n\n\u003chr style=\"border:none;border-top:1px solid #333;margin:28px 0;\"\u003e\n\n\u003ch3 style=\"color:#ffb74d;margin-bottom:10px;\"\u003eDecision 1 — Power Source: Battery or Plug-In?\u003c\/h3\u003e\n\n\u003cp style=\"color:#e0e0e0;\"\u003eThe power source determines where you can install a CO alarm and whether it works during a power outage — the most critical reliability question for residential CO protection. \u003cstrong\u003eBattery-powered alarms\u003c\/strong\u003e (\u003ca href=\"\/products\/first-alert-co410-battery-carbon-monoxide-alarm-with-digital-ppm-display-and-peak-memory\" style=\"color:#4fc3f7;\"\u003eCO710\u003c\/a\u003e, \u003ca href=\"\/products\/first-alert-co410-battery-carbon-monoxide-alarm-with-digital-ppm-display-and-peak-memory\" style=\"color:#4fc3f7;\"\u003eCO410\u003c\/a\u003e, \u003ca href=\"\/products\/first-alert-co250-battery-carbon-monoxide-alarm-with-tamper-resistant-cover\" style=\"color:#4fc3f7;\"\u003eCO511\u003c\/a\u003e, \u003ca href=\"\/products\/first-alert-co250-battery-carbon-monoxide-alarm-with-tamper-resistant-cover\" style=\"color:#4fc3f7;\"\u003eCO400\u003c\/a\u003e, \u003ca href=\"\/products\/first-alert-co250-battery-carbon-monoxide-alarm-with-tamper-resistant-cover\" style=\"color:#4fc3f7;\"\u003eCO250\u003c\/a\u003e) can go anywhere — nightstand, shelf, hallway — with no outlet required, and they never fail during a power outage. \u003cstrong\u003ePlug-in alarms with backup\u003c\/strong\u003e (\u003ca href=\"\/products\/first-alert-co410-battery-carbon-monoxide-alarm-with-digital-ppm-display-and-peak-memory\" style=\"color:#4fc3f7;\"\u003eCO615\u003c\/a\u003e, \u003ca href=\"\/products\/first-alert-co250-battery-carbon-monoxide-alarm-with-tamper-resistant-cover\" style=\"color:#4fc3f7;\"\u003eCO606\u003c\/a\u003e, \u003ca href=\"\/products\/first-alert-co250-battery-carbon-monoxide-alarm-with-tamper-resistant-cover\" style=\"color:#4fc3f7;\"\u003eGCO1\u003c\/a\u003e) draw from AC power in normal conditions and switch to battery backup automatically when power fails — combining always-on reliability with outage protection. The \u003ca href=\"\/products\/first-alert-co250-battery-carbon-monoxide-alarm-with-tamper-resistant-cover\" style=\"color:#4fc3f7;\"\u003eCO600\u003c\/a\u003e is the one model to avoid for residential use: AC-only with no battery backup, it fails exactly when CO risk is highest — during outages when generators and space heaters run indoors.\u003c\/p\u003e\n\n\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;color:#e0e0e0;margin:12px 0;font-size:0.88em;\"\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"padding:9px 12px;border:1px solid #333;color:#ffb74d;text-align:left;\"\u003e \u003c\/th\u003e\n\u003cth style=\"padding:9px 12px;border:1px solid #333;color:#ffb74d;text-align:center;\"\u003eSealed Battery (CO710)\u003c\/th\u003e\n\u003cth style=\"padding:9px 12px;border:1px solid #333;color:#ffb74d;text-align:center;\"\u003eReplaceable Battery (CO410, CO400)\u003c\/th\u003e\n\u003cth style=\"padding:9px 12px;border:1px solid #333;color:#ffb74d;text-align:center;\"\u003ePlug-In + Backup (CO615, CO606)\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;font-weight:700;color:#b0bec5;\"\u003eWorks during power outage\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;color:#81c784;\"\u003e✔ Always\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;color:#81c784;\"\u003e✔ Always\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;color:#81c784;\"\u003e✔ On backup\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#222;\"\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;font-weight:700;color:#b0bec5;\"\u003eBattery maintenance\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;color:#81c784;\"\u003eNone — 10 years\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;\"\u003eAnnual replacement\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;\"\u003eAnnual backup swap\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;font-weight:700;color:#b0bec5;\"\u003ePlacement flexibility\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;color:#81c784;\"\u003eAnywhere\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;color:#81c784;\"\u003eAnywhere\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;\"\u003eNear outlet\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#222;\"\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;font-weight:700;color:#b0bec5;\"\u003eBest for\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;\"\u003eZero-maintenance homes\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;\"\u003eBudget \/ supplemental\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;\"\u003ePrimary room coverage\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003chr style=\"border:none;border-top:1px solid #333;margin:28px 0;\"\u003e\n\n\u003ch3 style=\"color:#ffb74d;margin-bottom:10px;\"\u003eDecision 2 — Display and Diagnostics: Do You Need to See CO Levels?\u003c\/h3\u003e\n\n\u003cp style=\"color:#e0e0e0;\"\u003eUL 2034 alarm thresholds are set for healthy adults — the standard does not require an alarm below 70 PPM at 1–4 hours or below 150 PPM at 10–50 minutes. CO at 30–50 PPM sustained for hours is dangerous for infants, elderly occupants, and people with cardiovascular or respiratory conditions. A \u003cstrong\u003edigital display\u003c\/strong\u003e shows real-time PPM so you can act on rising CO before it reaches alarm thresholds. The \u003ca href=\"\/products\/first-alert-co410-battery-carbon-monoxide-alarm-with-digital-ppm-display-and-peak-memory\" style=\"color:#4fc3f7;\"\u003eCO710\u003c\/a\u003e displays PPM and room temperature; the \u003ca href=\"\/products\/first-alert-co410-battery-carbon-monoxide-alarm-with-digital-ppm-display-and-peak-memory\" style=\"color:#4fc3f7;\"\u003eCO615\u003c\/a\u003e and \u003ca href=\"\/products\/first-alert-co250-battery-carbon-monoxide-alarm-with-tamper-resistant-cover\" style=\"color:#4fc3f7;\"\u003eGCO1\u003c\/a\u003e display CO PPM. The \u003ca href=\"\/products\/first-alert-co410-battery-carbon-monoxide-alarm-with-digital-ppm-display-and-peak-memory\" style=\"color:#4fc3f7;\"\u003eCO410\u003c\/a\u003e adds \u003cstrong\u003epeak memory\u003c\/strong\u003e — it records the highest CO level ever measured, even when you weren't home — making it the best diagnostic tool for homes with a history of CO events or aging gas appliances. Models without displays (\u003ca href=\"\/products\/first-alert-co250-battery-carbon-monoxide-alarm-with-tamper-resistant-cover\" style=\"color:#4fc3f7;\"\u003eCO606\u003c\/a\u003e, \u003ca href=\"\/products\/first-alert-co250-battery-carbon-monoxide-alarm-with-tamper-resistant-cover\" style=\"color:#4fc3f7;\"\u003eCO400\u003c\/a\u003e, \u003ca href=\"\/products\/first-alert-co250-battery-carbon-monoxide-alarm-with-tamper-resistant-cover\" style=\"color:#4fc3f7;\"\u003eCO511\u003c\/a\u003e, \u003ca href=\"\/products\/first-alert-co250-battery-carbon-monoxide-alarm-with-tamper-resistant-cover\" style=\"color:#4fc3f7;\"\u003eCO250\u003c\/a\u003e) provide code-compliant protection and sound when thresholds are crossed — appropriate for most secondary placements and budget-conscious primary coverage.\u003c\/p\u003e\n\n\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;color:#e0e0e0;margin:12px 0;font-size:0.88em;\"\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"padding:9px 12px;border:1px solid #333;color:#ffb74d;text-align:left;\"\u003eModel\u003c\/th\u003e\n\u003cth style=\"padding:9px 12px;border:1px solid #333;color:#ffb74d;text-align:center;\"\u003eReal-Time PPM\u003c\/th\u003e\n\u003cth style=\"padding:9px 12px;border:1px solid #333;color:#ffb74d;text-align:center;\"\u003ePeak Memory\u003c\/th\u003e\n\u003cth style=\"padding:9px 12px;border:1px solid #333;color:#ffb74d;text-align:center;\"\u003eTemp Display\u003c\/th\u003e\n\u003cth style=\"padding:9px 12px;border:1px solid #333;color:#ffb74d;text-align:center;\"\u003eVoice Alert\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr style=\"background:#1e2a1e;\"\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;font-weight:700;\"\u003e\u003ca href=\"\/products\/first-alert-co410-battery-carbon-monoxide-alarm-with-digital-ppm-display-and-peak-memory\" style=\"color:#4fc3f7;\"\u003eCO710\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;color:#81c784;\"\u003e✔\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;\"\u003e—\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;color:#81c784;\"\u003e✔\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;\"\u003e—\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;font-weight:700;\"\u003e\u003ca href=\"\/products\/first-alert-co410-battery-carbon-monoxide-alarm-with-digital-ppm-display-and-peak-memory\" style=\"color:#4fc3f7;\"\u003eCO410\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;color:#81c784;\"\u003e✔\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;color:#81c784;\"\u003e✔\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;\"\u003e—\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;\"\u003e—\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#222;\"\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;font-weight:700;\"\u003e\u003ca href=\"\/products\/first-alert-co410-battery-carbon-monoxide-alarm-with-digital-ppm-display-and-peak-memory\" style=\"color:#4fc3f7;\"\u003eCO615\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;color:#81c784;\"\u003e✔\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;\"\u003e—\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;\"\u003e—\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;\"\u003e—\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;font-weight:700;\"\u003e\u003ca href=\"\/products\/first-alert-co250-battery-carbon-monoxide-alarm-with-tamper-resistant-cover\" style=\"color:#4fc3f7;\"\u003eGCO1\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;color:#81c784;\"\u003e✔\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;\"\u003e—\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;\"\u003e—\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;\"\u003e—\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#222;\"\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;font-weight:700;\"\u003e\u003ca href=\"\/products\/first-alert-co250-battery-carbon-monoxide-alarm-with-tamper-resistant-cover\" style=\"color:#4fc3f7;\"\u003eCO511\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;\"\u003e—\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;\"\u003e—\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;\"\u003e—\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;color:#81c784;\"\u003e✔\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;font-weight:700;\"\u003e\n\u003ca href=\"\/products\/first-alert-co250-battery-carbon-monoxide-alarm-with-tamper-resistant-cover\" style=\"color:#4fc3f7;\"\u003eCO606\u003c\/a\u003e \/ \u003ca href=\"\/products\/first-alert-co250-battery-carbon-monoxide-alarm-with-tamper-resistant-cover\" style=\"color:#4fc3f7;\"\u003eCO400\u003c\/a\u003e \/ \u003ca href=\"\/products\/first-alert-co250-battery-carbon-monoxide-alarm-with-tamper-resistant-cover\" style=\"color:#4fc3f7;\"\u003eCO250\u003c\/a\u003e\n\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;\"\u003e—\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;\"\u003e—\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;\"\u003e—\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;border:1px solid #333;text-align:center;\"\u003e—\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003chr style=\"border:none;border-top:1px solid #333;margin:28px 0;\"\u003e\n\n\u003ch3 style=\"color:#ffb74d;margin-bottom:10px;\"\u003eDecision 3 — Special Scenarios: Interconnect, Gas Appliances, or Rentals?\u003c\/h3\u003e\n\n\u003cp style=\"color:#e0e0e0;\"\u003eThree models in this collection address specific use cases that the standard battery or plug-in alarms do not cover:\u003c\/p\u003e\n\n\u003cul style=\"color:#e0e0e0;line-height:1.85;padding-left:1.4em;margin:10px 0 16px;\"\u003e\n  \u003cli\u003e\n\u003cstrong\u003e\u003ca href=\"\/products\/first-alert-co250-battery-carbon-monoxide-alarm-with-tamper-resistant-cover\" style=\"color:#4fc3f7;\"\u003eCO511 — Multi-story homes with a First Alert wireless network.\u003c\/a\u003e\u003c\/strong\u003e The CO511 wirelessly interconnects with compatible First Alert smoke and CO alarms so that when any alarm detects CO, all connected alarms sound simultaneously. A voice alert announces the threat type — clearer than a beep in the middle of the night. If CO in the basement needs to wake someone on the third floor, the CO511 is the model to add to your First Alert wireless alarm system.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e\u003ca href=\"\/products\/first-alert-co250-battery-carbon-monoxide-alarm-with-tamper-resistant-cover\" style=\"color:#4fc3f7;\"\u003eGCO1 — Homes with gas ranges, furnaces, or propane appliances.\u003c\/a\u003e\u003c\/strong\u003e The GCO1 adds combustible gas detection (natural gas, propane, methane) alongside CO detection in a single plug-in unit with 9V battery backup and digital CO display. Place it in the kitchen near a gas range, in a utility room near a gas furnace or water heater, or in a garage with gas-powered equipment. In rooms without gas appliances, a CO-only alarm is appropriate and more cost-effective.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e\u003ca href=\"\/products\/first-alert-co250-battery-carbon-monoxide-alarm-with-tamper-resistant-cover\" style=\"color:#4fc3f7;\"\u003eCO250 — Rental properties, dormitories, and managed facilities.\u003c\/a\u003e\u003c\/strong\u003e The CO250 uses a locking tamper-resistant cover that prevents occupants from removing the battery to silence nuisance chirps. Property managers retain the key, maintaining alarm integrity between inspections. If you manage rental units or institutional housing with a CO alarm compliance obligation, the CO250 addresses a documented real-world problem that standard alarms do not.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cblockquote style=\"border-left:4px solid #ff9800;background:#2a2520;padding:14px 18px;margin:16px 0;border-radius:4px;color:#f5e6d3;font-size:0.92em;\"\u003e\n\u003cstrong style=\"color:#ff9800;\"\u003eCO600 Warning — Not for Residential Use:\u003c\/strong\u003e The \u003ca href=\"\/products\/first-alert-co250-battery-carbon-monoxide-alarm-with-tamper-resistant-cover\" style=\"color:#4fc3f7;\"\u003eCO600\u003c\/a\u003e is an AC-only plug-in alarm with no battery backup. It stops functioning during power outages — when generators, portable heaters, and gas stoves used for warmth create the highest residential CO risk. At a nearly identical price, the \u003ca href=\"\/products\/first-alert-co250-battery-carbon-monoxide-alarm-with-tamper-resistant-cover\" style=\"color:#4fc3f7;\"\u003eCO606\u003c\/a\u003e adds 9V battery backup. There is no reason to choose the CO600 for a residence. It belongs only in commercial or institutional settings with guaranteed building backup power.\n\u003c\/blockquote\u003e\n\n\u003chr style=\"border:none;border-top:1px solid #333;margin:28px 0;\"\u003e\n\n\u003ch2 style=\"color:#e0e0e0;margin-bottom:16px;\"\u003eFrequently Asked Questions — First Alert CO Alarms\u003c\/h2\u003e\n\n\u003cdetails style=\"background:#1a1a1a;border:1px solid #333;border-radius:4px;padding:12px 16px;margin:8px 0;\"\u003e\n\u003csummary style=\"color:#ff9800;font-weight:700;cursor:pointer;\"\u003eWhich First Alert CO alarm is best for most homes?\u003c\/summary\u003e\n\u003cp style=\"color:#e0e0e0;margin-top:10px;\"\u003eThe \u003ca href=\"\/products\/first-alert-co410-battery-carbon-monoxide-alarm-with-digital-ppm-display-and-peak-memory\" style=\"color:#4fc3f7;\"\u003eCO710\u003c\/a\u003e is the best overall choice for most households. Its sealed 10-year lithium battery eliminates annual replacements; the digital display shows real-time CO PPM and room temperature; and the 10-year warranty matches the alarm's full service life. It's freestanding — no mounting needed, renter-friendly. If zero battery maintenance and a display aren't priorities, the \u003ca href=\"\/products\/first-alert-co250-battery-carbon-monoxide-alarm-with-tamper-resistant-cover\" style=\"color:#4fc3f7;\"\u003eCO606\u003c\/a\u003e (plug-in + 9V backup) delivers code-compliant protection at the lowest plug-in cost.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails style=\"background:#1a1a1a;border:1px solid #333;border-radius:4px;padding:12px 16px;margin:8px 0;\"\u003e\n\u003csummary style=\"color:#ff9800;font-weight:700;cursor:pointer;\"\u003eHow many CO alarms does my home need?\u003c\/summary\u003e\n\u003cp style=\"color:#e0e0e0;margin-top:10px;\"\u003eNFPA 720 requires a CO alarm on each level of the home (including basements) and within 10 feet of each sleeping area. A two-story, three-bedroom home typically needs a minimum of four alarms: one per bedroom and one per additional floor. Many states have adopted NFPA 720 or similar requirements into residential code; check your local building or fire code for the specific requirement in your jurisdiction. If you have an attached garage, a CO alarm near the interior garage door is advisable even if not code-required — CO from an idling vehicle can migrate into living spaces within minutes.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails style=\"background:#1a1a1a;border:1px solid #333;border-radius:4px;padding:12px 16px;margin:8px 0;\"\u003e\n\u003csummary style=\"color:#ff9800;font-weight:700;cursor:pointer;\"\u003eWhat is UL 2034 and why does it matter?\u003c\/summary\u003e\n\u003cp style=\"color:#e0e0e0;margin-top:top:10px;\"\u003eUL 2034 is the residential CO alarm standard published by Underwriters Laboratories. It defines the CO concentration levels and time durations at which an alarm must sound — for example, the alarm must activate at 70 PPM after 60–240 minutes, at 150 PPM after 10–50 minutes, and at 400 PPM within 4–15 minutes. Every model in this collection is UL 2034 listed. Most state residential CO alarm codes require UL 2034 listing; non-listed alarms do not meet code regardless of stated function. All nine First Alert models in this collection satisfy this requirement.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails style=\"background:#1a1a1a;border:1px solid #333;border-radius:4px;padding:12px 16px;margin:8px 0;\"\u003e\n\u003csummary style=\"color:#ff9800;font-weight:700;cursor:pointer;\"\u003eIs there a difference between a CO alarm and a CO detector?\u003c\/summary\u003e\n\u003cp style=\"color:#e0e0e0;margin-top:10px;\"\u003eIn residential use, the terms are used interchangeably. All nine models in this collection are alarms — they detect CO and respond with an 85 dB audible signal when threshold levels are reached. In professional settings, \"CO detector\" sometimes refers to a monitoring device used for continuous measurement and data logging without a built-in audible alarm. For homes, any UL 2034 listed unit with an audible alarm meets the definition of a CO alarm under residential codes.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails style=\"background:#1a1a1a;border:1px solid #333;border-radius:4px;padding:12px 16px;margin:8px 0;\"\u003e\n\u003csummary style=\"color:#ff9800;font-weight:700;cursor:pointer;\"\u003eWhere should I place a CO alarm — high or low on the wall?\u003c\/summary\u003e\n\u003cp style=\"color:#e0e0e0;margin-top:10px;\"\u003eUnlike smoke, CO is slightly lighter than air but distributes nearly evenly throughout a room — high-wall or ceiling mounting is not required. First Alert recommends placing CO alarms at least 5 feet from the floor to avoid interference from ground-level drafts. NFPA 720 permits placement at any height in a room. The most important placement rule is distance from sleeping areas: within 10 feet of each bedroom door. CO alarms should never be placed directly adjacent to fuel-burning appliances, inside bathrooms, or in areas of high humidity or extreme temperature.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails style=\"background:#1a1a1a;border:1px solid #333;border-radius:4px;padding:12px 16px;margin:8px 0;\"\u003e\n\u003csummary style=\"color:#ff9800;font-weight:700;cursor:pointer;\"\u003eHow long do First Alert CO alarms last?\u003c\/summary\u003e\n\u003cp style=\"color:#e0e0e0;margin-top:10px;\"\u003eThe electrochemical CO sensor in most First Alert residential alarms has a rated service life of 5–7 years. Warranty terms reflect this: the CO400 and GCO1 carry 5-year warranties; most other models in this collection carry 7-year warranties; the CO710 has a 10-year warranty matching its sealed battery life. When the end-of-life alarm activates, replace the unit — do not silence and continue using it. An aging electrochemical sensor may fail to detect CO reliably even though the audible circuitry continues to function.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails style=\"background:#1a1a1a;border:1px solid #333;border-radius:4px;padding:12px 16px;margin:8px 0;\"\u003e\n\u003csummary style=\"color:#ff9800;font-weight:700;cursor:pointer;\"\u003eWhat should I do when a CO alarm sounds?\u003c\/summary\u003e\n\u003cp style=\"color:#e0e0e0;margin-top:10px;\"\u003eIf your CO alarm activates: (1) Do not ignore it or assume it is a false alarm. (2) Immediately move all occupants and pets outside to fresh air. (3) Call 911 or your local emergency number from outside. (4) Do not re-enter the building until emergency responders have investigated and cleared it. (5) If a CO source is identified (a running generator indoors, a malfunctioning furnace), do not operate it again until it has been inspected and repaired by a licensed professional. CO is colorless and odorless — there is no safe way to verify an alarm is false without proper equipment.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails style=\"background:#1a1a1a;border:1px solid #333;border-radius:4px;padding:12px 16px;margin:8px 0;\"\u003e\n\u003csummary style=\"color:#ff9800;font-weight:700;cursor:pointer;\"\u003eCan I use a First Alert CO alarm in an RV or boat?\u003c\/summary\u003e\n\u003cp style=\"color:#e0e0e0;margin-top:10px;\"\u003eBattery-powered First Alert CO alarms (\u003ca href=\"\/products\/first-alert-co410-battery-carbon-monoxide-alarm-with-digital-ppm-display-and-peak-memory\" style=\"color:#4fc3f7;\"\u003eCO710\u003c\/a\u003e, \u003ca href=\"\/products\/first-alert-co410-battery-carbon-monoxide-alarm-with-digital-ppm-display-and-peak-memory\" style=\"color:#4fc3f7;\"\u003eCO410\u003c\/a\u003e, \u003ca href=\"\/products\/first-alert-co250-battery-carbon-monoxide-alarm-with-tamper-resistant-cover\" style=\"color:#4fc3f7;\"\u003eCO400\u003c\/a\u003e) can be used in RVs where they are placed in stable locations away from heat sources, cooking appliances, and high-vibration areas. They are not specifically certified for marine use. For boats and marine applications, look for CO alarms carrying UL 2034 plus UL 1524 marine listing. For RVs, some states and RV manufacturers specify alarm requirements — check applicable codes before installation.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails style=\"background:#1a1a1a;border:1px solid #333;border-radius:4px;padding:12px 16px;margin:8px 0;\"\u003e\n\u003csummary style=\"color:#ff9800;font-weight:700;cursor:pointer;\"\u003eDo I need both a smoke alarm and a CO alarm?\u003c\/summary\u003e\n\u003cp style=\"color:#e0e0e0;margin-top:10px;\"\u003eYes — they are different sensors detecting different hazards. CO alarms detect colorless, odorless carbon monoxide gas from combustion sources. Smoke alarms detect particles from burning. A CO alarm will not detect smoke, and a smoke alarm will not detect CO. Both are required by residential codes in most states. Combination smoke\/CO alarms exist, but the nine models in this First Alert CO-only collection are dedicated CO alarms optimized for CO detection — if you want combination units, see the combination alarm category.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails style=\"background:#1a1a1a;border:1px solid #333;border-radius:4px;padding:12px 16px;margin:8px 0;\"\u003e\n\u003csummary style=\"color:#ff9800;font-weight:700;cursor:pointer;\"\u003eWhat causes a CO alarm to chirp even when no CO is present?\u003c\/summary\u003e\n\u003cp style=\"color:#e0e0e0;margin-top:10px;\"\u003eA single chirp every 30–60 seconds is almost always a low-battery signal, not a CO alert. Replace the battery and the chirping should stop. A series of 4 chirps in a pattern (distinct from the continuous alarm tone) is the CO alarm — take this seriously and evacuate. A chirp pattern of 5 beeps every minute indicates the end-of-life signal — replace the entire unit. Never remove the battery to stop chirping without first identifying the chirp pattern: a low-battery chirp is a maintenance reminder, but the CO alarm and end-of-life chirp both require immediate action.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003chr style=\"border:none;border-top:1px solid #333;margin:28px 0;\"\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border:1px solid #333;border-radius:6px;padding:16px 20px;margin:0 0 8px;\"\u003e\n\u003cp style=\"color:#ffb74d;font-weight:700;margin:0 0 10px;font-size:0.95em;\"\u003eRelated Collections \u0026amp; Guides\u003c\/p\u003e\n\u003cul style=\"color:#e0e0e0;margin:0;padding-left:1.4em;line-height:2.0;font-size:0.9em;\"\u003e\n  \u003cli\u003e\n\u003ca href=\"https:\/\/wcsafety.com\/collections\/kidde-carbon-monoxide-alarms-detectors\" style=\"color:#4fc3f7;\"\u003eKidde Carbon Monoxide Alarms\u003c\/a\u003e — 34 models including Worry-Free sealed battery, smart WiFi (COPDLQW), and CO + gas detection\u003c\/li\u003e\n  \u003cli\u003e\n\u003ca href=\"https:\/\/wcsafety.com\/blogs\/product-reviews\/co710-first-alert-10-year-sealed-battery-co-alarm-digital-display-review\" style=\"color:#4fc3f7;\"\u003eCO710 Review\u003c\/a\u003e — Detailed review: sealed battery, display specs, who should buy it\u003c\/li\u003e\n  \u003cli\u003e\n\u003ca href=\"https:\/\/wcsafety.com\/blogs\/product-reviews\/co615-first-alert-plug-in-co-alarm-battery-backup-digital-display-review\" style=\"color:#4fc3f7;\"\u003eCO615 Review\u003c\/a\u003e — 6-foot cord, AA backup, and when to choose it over the CO606\u003c\/li\u003e\n  \u003cli\u003e\n\u003ca href=\"https:\/\/wcsafety.com\/blogs\/product-reviews\/co511-first-alert-wireless-interconnect-co-alarm-voice-alert-review\" style=\"color:#4fc3f7;\"\u003eCO511 Review\u003c\/a\u003e — Wireless interconnect setup, network limits, voice alert details\u003c\/li\u003e\n  \u003cli\u003e\n\u003ca href=\"https:\/\/wcsafety.com\/blogs\/product-reviews\/gco1-first-alert-combination-co-explosive-gas-alarm-review\" style=\"color:#4fc3f7;\"\u003eGCO1 Review\u003c\/a\u003e — CO + gas dual detection: placement, warranty, and vs. Kidde KN-COEG-3\u003c\/li\u003e\n  \u003cli\u003e\n\u003ca href=\"https:\/\/wcsafety.com\/blogs\/product-reviews\/co410-first-alert-battery-co-alarm-digital-display-peak-memory-review\" style=\"color:#4fc3f7;\"\u003eCO410 Review\u003c\/a\u003e — Peak memory explained and when it justifies the upgrade from CO400\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n","products":[{"product_id":"first-alert-gco1-combination-carbon-monoxide-and-explosive-gas-alarm","title":"First Alert GCO1 Combination Carbon Monoxide and Explosive Gas Alarm","description":"\u003cp\u003eThe \u003cstrong\u003eFirst Alert GCO1 Combination Carbon Monoxide and Explosive Gas Alarm\u003c\/strong\u003e provides dual protection against two invisible household dangers: carbon monoxide poisoning and combustible gas leaks. This plug-in detector continuously monitors for CO as well as propane, natural gas, and methane, sounding an 85dB alarm before dangerous levels build up.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eDetects both carbon monoxide AND combustible gases (propane, natural gas, methane)\u003c\/li\u003e\n\u003cli\u003ePlug-in with 9-volt battery backup ensures protection during power outages\u003c\/li\u003e\n\u003cli\u003eBacklit digital display shows current CO levels at a glance\u003c\/li\u003e\n\u003cli\u003eLoud 85dB alarm horn alerts the whole household\u003c\/li\u003e\n\u003cli\u003e5-year limited warranty\u003c\/li\u003e\n\u003cli\u003eDimensions: 5.6\" x 3.1\" x 1.8\"\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eMeets UL 2075 standard for gas and carbon monoxide alarms. Ideal for homes with gas appliances, fireplaces, or attached garages.\u003c\/p\u003e","brand":"First Alert","offers":[{"title":"Default Title","offer_id":44089212469336,"sku":null,"price":0.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0594\/1900\/0920\/files\/41GE7BGfEwL._SL500.jpg?v=1778350205"},{"product_id":"first-alert-co710-10-year-sealed-battery-carbon-monoxide-alarm-with-digital-display","title":"First Alert CO710 10-Year Sealed Battery Carbon Monoxide Alarm with Digital Display","description":"\u003cp\u003eThe \u003cstrong\u003eFirst Alert CO710 10-Year Sealed Battery Carbon Monoxide Alarm\u003c\/strong\u003e eliminates the hassle of ever replacing batteries. The sealed lithium battery lasts the life of the alarm - 10 full years - so you always have protection without the maintenance.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e10-year sealed lithium battery - never replace batteries for the life of the alarm\u003c\/li\u003e\n\u003cli\u003eDigital display shows current CO concentration in PPM and room temperature\u003c\/li\u003e\n\u003cli\u003ePortable design requires no mounting - place it anywhere in your home\u003c\/li\u003e\n\u003cli\u003eLoud 85dB alarm and end-of-life signal alert you when replacement is due\u003c\/li\u003e\n\u003cli\u003e10-year limited warranty\u003c\/li\u003e\n\u003cli\u003eDimensions: 4.75\" wide x 2.63\" tall\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003ePerfect for renters, frequent movers, or anyone who wants truly maintenance-free CO protection. Meets UL 2034 safety standards.\u003c\/p\u003e","brand":"First Alert","offers":[{"title":"Default Title","offer_id":44089212502104,"sku":null,"price":0.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0594\/1900\/0920\/files\/31nTt1fWXCL._SL500.jpg?v=1778350213"},{"product_id":"first-alert-co615-plug-in-carbon-monoxide-alarm-with-battery-backup-and-digital-display","title":"First Alert CO615 Plug-In Carbon Monoxide Alarm with Battery Backup and Digital Display","description":"\u003cp\u003eThe \u003cstrong\u003eFirst Alert CO615 Plug-In Carbon Monoxide Alarm with Battery Backup\u003c\/strong\u003e delivers continuous AC-powered protection with a convenient 6-foot power cord, plus 2 AA batteries keep it running through power outages.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003ePlug-in design with 6-foot cord for flexible outlet placement\u003c\/li\u003e\n\u003cli\u003e2 AA battery backup maintains protection during power failures\u003c\/li\u003e\n\u003cli\u003eBacklit digital display shows real-time CO concentration levels\u003c\/li\u003e\n\u003cli\u003eLoud 85dB alarm provides whole-home audible alert\u003c\/li\u003e\n\u003cli\u003e7-year limited warranty\u003c\/li\u003e\n\u003cli\u003eDimensions: 5\" x 3.4\" x 1.7\"\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eThe combination of plug-in convenience and battery backup makes the CO615 one of the most reliable carbon monoxide detectors for any home. Meets UL 2034 safety standards.\u003c\/p\u003e","brand":"First Alert","offers":[{"title":"Default Title","offer_id":44089212698712,"sku":null,"price":0.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0594\/1900\/0920\/files\/318JfCYvBKL._SL500.jpg?v=1778350222"},{"product_id":"first-alert-co511-wireless-interconnect-carbon-monoxide-alarm-with-voice-alert","title":"First Alert CO511 Wireless Interconnect Carbon Monoxide Alarm with Voice Alert","description":"\u003cp\u003eThe \u003cstrong\u003eFirst Alert CO511 Wireless Interconnect Carbon Monoxide Alarm\u003c\/strong\u003e takes CO safety to the next level - when one alarm sounds, all compatible First Alert wireless alarms sound together throughout your home, so you're alerted no matter where you are.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eWirelessly interconnects with other compatible First Alert smoke and CO alarms\u003c\/li\u003e\n\u003cli\u003eVoice alert announces the type of threat and its location\u003c\/li\u003e\n\u003cli\u003ePowered by 2 AA batteries with low-battery warning\u003c\/li\u003e\n\u003cli\u003eLoud 85dB alarm for immediate household-wide alert\u003c\/li\u003e\n\u003cli\u003e7-year limited warranty\u003c\/li\u003e\n\u003cli\u003eDimensions: 5.13\" x 5.13\" x 2.38\"\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eIdeal for multi-story homes and larger spaces. No wiring required - wireless interconnect works out of the box. Meets UL 2034 safety standards.\u003c\/p\u003e","brand":"First Alert","offers":[{"title":"Default Title","offer_id":44089212731480,"sku":null,"price":0.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0594\/1900\/0920\/files\/31WUPpG-ZXL._SL500.jpg?v=1778350229"},{"product_id":"first-alert-co410-battery-carbon-monoxide-alarm-with-digital-ppm-display-and-peak-memory","title":"First Alert CO410 Battery Carbon Monoxide Alarm with Digital PPM Display and Peak Memory","description":"\u003cp\u003eThe \u003cstrong\u003eFirst Alert CO410 Battery-Powered Carbon Monoxide Alarm with Digital Display\u003c\/strong\u003e gives you precise, real-time CO readings and a peak-level memory feature that records the highest CO concentration detected - invaluable for identifying intermittent leaks.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eBacklit digital display shows real-time CO concentration in parts per million (PPM)\u003c\/li\u003e\n\u003cli\u003ePeak CO memory records and displays the highest CO level detected\u003c\/li\u003e\n\u003cli\u003ePowered by 2 AA batteries for easy, cord-free placement\u003c\/li\u003e\n\u003cli\u003e85dB alarm audible throughout the home\u003c\/li\u003e\n\u003cli\u003e7-year limited warranty\u003c\/li\u003e\n\u003cli\u003eDimensions: 5\" x 3.4\" x 1.5\"\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eThe peak memory function helps homeowners and technicians pinpoint CO sources that occur only at certain times. Meets UL 2034 safety standards.\u003c\/p\u003e","brand":"First Alert","offers":[{"title":"Default Title","offer_id":44089212797016,"sku":null,"price":0.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0594\/1900\/0920\/files\/31ixpWOi86L._SL500.jpg?v=1778350234"},{"product_id":"first-alert-co606-plug-in-carbon-monoxide-alarm-with-9v-battery-backup","title":"First Alert CO606 Plug-In Carbon Monoxide Alarm with 9V Battery Backup","description":"\u003cp\u003e\u003cstrong\u003eShort answer:\u003c\/strong\u003e The CO606 is the best of both worlds in First Alert's lineup — it plugs into a standard 120V outlet for permanent installation, but the included 9V battery backup keeps it running during power outages. This matters because power outages are exactly when CO risk spikes: people run generators indoors, use propane heaters, or light candles near gas appliances. If you're choosing between the CO600 and CO606 for a permanent installation, the CO606 is the right call.\u003c\/p\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border-left:4px solid #ff9800;border-radius:4px;padding:16px 20px;margin:24px 0;\"\u003e\n\u003cstrong style=\"color:#ff9800;\"\u003eKey specs at a glance\u003c\/strong\u003e\n\u003cul style=\"margin-top:10px;padding-left:18px;line-height:2;color:#e0e0e0;\"\u003e\n\u003cli\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003ePower:\u003c\/strong\u003e 120V AC plug-in primary power\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eBackup:\u003c\/strong\u003e 9V battery — maintains protection during power outages\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eSensor:\u003c\/strong\u003e Electrochemical CO sensor\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eAlarm Output:\u003c\/strong\u003e 85dB at 10 feet\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eControls:\u003c\/strong\u003e Single test\/silence button\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eListing:\u003c\/strong\u003e UL 2034\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eWarranty:\u003c\/strong\u003e 7-year limited\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eWhy Battery Backup Matters for CO Detection\u003c\/h2\u003e\n\u003cdiv style=\"background:#1a1a1a;border-left:4px solid #ef4444;border-radius:4px;padding:16px 20px;margin:24px 0;\"\u003e\n\u003cstrong style=\"color:#ef4444;\"\u003eGenerator use is the #1 source of CO fatalities in the US\u003c\/strong\u003e\n\u003cp style=\"color:#e0e0e0;margin-top:8px;\"\u003eWhen the power goes out, households turn to generators, propane heaters, and gas stoves. These devices produce CO. A plug-in CO alarm with no battery backup goes offline at exactly the moment the risk increases. The CO606 addresses this directly — its 9V backup battery activates automatically when AC power is lost.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eFirst Alert CO Alarm Comparison\u003c\/h2\u003e\n\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;color:#e0e0e0;margin:16px 0;font-size:0.9em;\"\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"padding:10px 12px;border:1px solid #333;color:#ffb74d;text-align:left;\"\u003eModel\u003c\/th\u003e\n\u003cth style=\"padding:10px 12px;border:1px solid #333;color:#ffb74d;text-align:center;\"\u003ePower\u003c\/th\u003e\n\u003cth style=\"padding:10px 12px;border:1px solid #333;color:#ffb74d;text-align:center;\"\u003eOutage Protection\u003c\/th\u003e\n\u003cth style=\"padding:10px 12px;border:1px solid #333;color:#ffb74d;text-align:center;\"\u003eWarranty\u003c\/th\u003e\n\u003cth style=\"padding:10px 12px;border:1px solid #333;color:#ffb74d;text-align:left;\"\u003eBest For\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;\"\u003eCO400\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;text-align:center;\"\u003e9V battery only\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;text-align:center;\"\u003eYes (is battery)\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;text-align:center;\"\u003e5 yr\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;\"\u003eOutlet-free locations, RVs, supplemental\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#222;\"\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;\"\u003eCO600\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;text-align:center;\"\u003e120V AC\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;text-align:center;\"\u003eNo\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;text-align:center;\"\u003e7 yr\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;\"\u003ePermanent install, no battery maintenance\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#1e2a1e;\"\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;font-weight:bold;\"\u003eCO606 ★\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;text-align:center;\"\u003e120V AC + 9V backup\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;text-align:center;font-weight:bold;\"\u003eYes\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;text-align:center;\"\u003e7 yr\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;font-weight:bold;\"\u003eRecommended permanent install — full coverage\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eInstallation Guide\u003c\/h2\u003e\n\u003cul style=\"line-height:2;color:#e0e0e0;padding-left:18px;\"\u003e\n\u003cli\u003eInstall the 9V backup battery before plugging in\u003c\/li\u003e\n\u003cli\u003ePlug into a standard 120V outlet — unit activates immediately\u003c\/li\u003e\n\u003cli\u003ePress the test button to verify alarm function\u003c\/li\u003e\n\u003cli\u003eMount height: 5 feet from floor on walls near outlets, or on outlet covers at outlet height — CO disperses throughout the room, not just at ceiling level\u003c\/li\u003e\n\u003cli\u003eRequired locations: outside each sleeping area and on each level of the home (NFPA 720)\u003c\/li\u003e\n\u003cli\u003eReplace backup battery annually — the unit will chirp to signal low battery\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003ch4\u003eHow do I know the battery backup is working?\u003c\/h4\u003e\n\u003cp\u003ePress the test button — it tests both AC power detection and battery backup. If the backup battery is low or missing, the CO606 will emit a distinct low-battery chirp pattern (different from the alarm and end-of-life signals).\u003c\/p\u003e\n\n\u003ch4\u003eCan I use a rechargeable 9V battery in the CO606?\u003c\/h4\u003e\n\u003cp\u003eFirst Alert recommends standard alkaline 9V batteries only. Rechargeable batteries have a lower voltage output that may not provide sufficient power for reliable backup operation.\u003c\/p\u003e\n\n\u003ch4\u003eWhat's the end-of-life signal?\u003c\/h4\u003e\n\u003cp\u003eAfter approximately 7 years, the electrochemical sensor degrades to a point where accurate CO detection is no longer reliable. The CO606 emits a specific chirp pattern (typically 5 chirps every 30 seconds) that differs from the low-battery or CO alarm patterns, indicating the unit should be replaced. Do not silence and continue using a unit that has issued an end-of-life warning.\u003c\/p\u003e\n\n\u003ch4\u003eIs the CO606 interconnectable with other alarms?\u003c\/h4\u003e\n\u003cp\u003eThe CO606 is not designed for hardwired interconnect. For interconnected systems (where all alarms sound when one detects CO), look for First Alert models with the OneLink wireless interconnect feature or hardwired interconnect capability.\u003c\/p\u003e\n\n\u003ch4\u003eHow does it meet UL 2034?\u003c\/h4\u003e\n\u003cp\u003eUL 2034 is the Underwriters Laboratories standard for single and multiple station CO alarms. It specifies alarm thresholds that prevent nuisance alarms at low CO levels while ensuring alarm at concentrations that pose health risk. The CO606 is UL 2034 listed, satisfying the requirements referenced by NFPA 720 and most state CO alarm codes.\u003c\/p\u003e\u003c!--wcs-deorphan-all-v1--\u003e\u003cdiv style=\"background:#1a2733;border-left:4px solid #ffb74d;border-radius:8px;padding:14px 18px;margin:20px 0;color:#e0e0e0;\"\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eRelated Products \u0026amp; Guides\u003c\/strong\u003e\u003cul style=\"padding-left:20px;margin:8px 0 0;\"\u003e\n\u003cli style=\"margin:5px 0;\"\u003e\u003ca href=\"\/collections\/co-detectors\" style=\"color:#4fc3f7;text-decoration:underline;\"\u003eco detectors\u003c\/a\u003e\u003c\/li\u003e\n\u003cli style=\"margin:5px 0;\"\u003e\u003ca href=\"\/collections\/first-alert-carbon-monoxide-alarms-detectors\" style=\"color:#4fc3f7;text-decoration:underline;\"\u003efirst alert carbon monoxide alarms detectors\u003c\/a\u003e\u003c\/li\u003e\n\u003cli style=\"margin:5px 0;\"\u003e\u003ca href=\"\/collections\/home-safety\" style=\"color:#4fc3f7;text-decoration:underline;\"\u003ehome safety\u003c\/a\u003e\u003c\/li\u003e\n\u003cli style=\"margin:5px 0;\"\u003e\u003ca href=\"\/blogs\/guides\/best-carbon-monoxide-detector-2026\" style=\"color:#4fc3f7;text-decoration:underline;\"\u003ebest carbon monoxide detector 2026\u003c\/a\u003e\u003c\/li\u003e\n\u003cli style=\"margin:5px 0;\"\u003e\u003ca href=\"\/blogs\/guides\/best-smoke-detectors-2026\" style=\"color:#4fc3f7;text-decoration:underline;\"\u003ebest smoke detectors 2026\u003c\/a\u003e\u003c\/li\u003e\n\u003cli style=\"margin:5px 0;\"\u003e\u003ca href=\"\/products\/first-alert-gco1-combination-carbon-monoxide-and-explosive-gas-alarm\" style=\"color:#4fc3f7;text-decoration:underline;\"\u003eFirst Alert GCO1 Combination Carbon Monoxide a\u003c\/a\u003e\u003c\/li\u003e\n\u003cli style=\"margin:5px 0;\"\u003e\u003ca href=\"\/products\/first-alert-co710-10-year-sealed-battery-carbon-monoxide-alarm-with-digital-display\" style=\"color:#4fc3f7;text-decoration:underline;\"\u003eFirst Alert CO710 10-Year Sealed Battery Carbo\u003c\/a\u003e\u003c\/li\u003e\n\u003cli style=\"margin:5px 0;\"\u003e\u003ca href=\"\/products\/first-alert-co615-plug-in-carbon-monoxide-alarm-with-battery-backup-and-digital-display\" style=\"color:#4fc3f7;text-decoration:underline;\"\u003eFirst Alert CO615 Plug-In Carbon Monoxide Alar\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e","brand":"First Alert","offers":[{"title":"Default Title","offer_id":44089212895320,"sku":null,"price":0.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0594\/1900\/0920\/files\/31xKO7zoB2L._SL500.jpg?v=1778350240"},{"product_id":"first-alert-co400-battery-powered-carbon-monoxide-alarm-with-9v-battery","title":"First Alert CO400 Battery-Powered Carbon Monoxide Alarm with 9V Battery","description":"\u003cp\u003e\u003cstrong\u003eShort answer:\u003c\/strong\u003e The CO400 is First Alert's entry-level battery-powered CO alarm — powered by a single 9V battery, no outlet required, place it anywhere. If you need a no-frills detector for a bedroom, RV, camper, or a location away from outlets, the CO400 is the right choice. If you have AC power available and want a permanent installation, the CO606 (plug-in with battery backup) is a better long-term option.\u003c\/p\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border-left:4px solid #ff9800;border-radius:4px;padding:16px 20px;margin:24px 0;\"\u003e\n\u003cstrong style=\"color:#ff9800;\"\u003eKey specs at a glance\u003c\/strong\u003e\n\u003cul style=\"margin-top:10px;padding-left:18px;line-height:2;color:#e0e0e0;\"\u003e\n\u003cli\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003ePower:\u003c\/strong\u003e 1 × 9V battery (included)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eSensor:\u003c\/strong\u003e Electrochemical CO sensor\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eAlarm Output:\u003c\/strong\u003e 85dB at 10 feet\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eListing:\u003c\/strong\u003e UL 2034 — the required standard for residential CO alarms\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eWarranty:\u003c\/strong\u003e 5-year limited\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eOperation:\u003c\/strong\u003e Single test\/silence button\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eCO400 vs CO600 vs CO606 — Which One to Buy\u003c\/h2\u003e\n\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;color:#e0e0e0;margin:16px 0;font-size:0.9em;\"\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"padding:10px 12px;border:1px solid #333;color:#ffb74d;text-align:left;\"\u003eModel\u003c\/th\u003e\n\u003cth style=\"padding:10px 12px;border:1px solid #333;color:#ffb74d;text-align:center;\"\u003ePower\u003c\/th\u003e\n\u003cth style=\"padding:10px 12px;border:1px solid #333;color:#ffb74d;text-align:center;\"\u003eBackup\u003c\/th\u003e\n\u003cth style=\"padding:10px 12px;border:1px solid #333;color:#ffb74d;text-align:center;\"\u003eWarranty\u003c\/th\u003e\n\u003cth style=\"padding:10px 12px;border:1px solid #333;color:#ffb74d;text-align:left;\"\u003eBest For\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr style=\"background:#1e2a1e;\"\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;font-weight:bold;\"\u003eCO400 ★\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;text-align:center;\"\u003e9V battery\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;text-align:center;\"\u003eN\/A\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;text-align:center;\"\u003e5 yr\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;\"\u003eNo-outlet locations, RVs, supplemental use\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#222;\"\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;\"\u003eCO600\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;text-align:center;\"\u003eAC plug-in\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;text-align:center;\"\u003eNone\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;text-align:center;\"\u003e7 yr\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;\"\u003eNear-outlet permanent install, no outage concern\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;\"\u003eCO606\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;text-align:center;\"\u003eAC plug-in\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;text-align:center;\"\u003e9V battery\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;text-align:center;\"\u003e7 yr\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;\"\u003ePermanent install with power outage protection\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWhere to Place a CO Alarm\u003c\/h2\u003e\n\u003cul style=\"line-height:2;color:#e0e0e0;padding-left:18px;\"\u003e\n\u003cli\u003e\n\u003cstrong\u003eOutside every sleeping area:\u003c\/strong\u003e NFPA 720 and most local codes require CO alarms on each level and outside each sleeping area\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEach level of the home:\u003c\/strong\u003e CO can accumulate on any floor depending on source location\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNear attached garages:\u003c\/strong\u003e Vehicle exhaust is a major residential CO source\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot in kitchens or near cooking appliances:\u003c\/strong\u003e Combustion products from normal cooking can trigger false alarms\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot in high-humidity areas:\u003c\/strong\u003e Steam from bathrooms can shorten sensor life\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003ch4\u003eHow long does the battery last?\u003c\/h4\u003e\n\u003cp\u003eFirst Alert states the CO400 provides approximately 1 year of battery life from a standard 9V alkaline battery. The unit will chirp to indicate a low battery before protection is lost.\u003c\/p\u003e\n\n\u003ch4\u003eDoes the CO400 also detect smoke?\u003c\/h4\u003e\n\u003cp\u003eNo — the CO400 detects carbon monoxide only. For complete protection, pair it with a separate smoke alarm. First Alert offers combination smoke\/CO alarms if you prefer a single unit.\u003c\/p\u003e\n\n\u003ch4\u003eWhen does the alarm trigger?\u003c\/h4\u003e\n\u003cp\u003ePer UL 2034 requirements, the CO400 alarms based on CO concentration over time: 70 ppm for 1–4 hours, 150 ppm within 10–50 minutes, or 400 ppm within 4–15 minutes. It will not alarm at CO levels below 70 ppm, which prevents false alarms from brief ambient exposure.\u003c\/p\u003e\n\n\u003ch4\u003eIs the CO400 required by code?\u003c\/h4\u003e\n\u003cp\u003eCO alarm requirements vary by state and locality. As of 2026, most states with CO alarm laws require detectors outside sleeping areas and on each level. Check your local building or fire code — many jurisdictions now require CO alarms in all new construction and rental properties.\u003c\/p\u003e\n\n\u003ch4\u003eHow do I know when to replace it?\u003c\/h4\u003e\n\u003cp\u003eThe CO400 has a 5-year warranty and the electrochemical sensor has a limited lifespan. After 5–7 years, the sensor degrades and the unit should be replaced. First Alert builds in an end-of-life warning chirp pattern that differs from the low-battery chirp.\u003c\/p\u003e\u003c!--wcs-deorphan-all-v1--\u003e\u003cdiv style=\"background:#1a2733;border-left:4px solid #ffb74d;border-radius:8px;padding:14px 18px;margin:20px 0;color:#e0e0e0;\"\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eRelated Products \u0026amp; Guides\u003c\/strong\u003e\u003cul style=\"padding-left:20px;margin:8px 0 0;\"\u003e\n\u003cli style=\"margin:5px 0;\"\u003e\u003ca href=\"\/collections\/co-detectors\" style=\"color:#4fc3f7;text-decoration:underline;\"\u003eco detectors\u003c\/a\u003e\u003c\/li\u003e\n\u003cli style=\"margin:5px 0;\"\u003e\u003ca href=\"\/collections\/first-alert-carbon-monoxide-alarms-detectors\" style=\"color:#4fc3f7;text-decoration:underline;\"\u003efirst alert carbon monoxide alarms detectors\u003c\/a\u003e\u003c\/li\u003e\n\u003cli style=\"margin:5px 0;\"\u003e\u003ca href=\"\/collections\/home-safety\" style=\"color:#4fc3f7;text-decoration:underline;\"\u003ehome safety\u003c\/a\u003e\u003c\/li\u003e\n\u003cli style=\"margin:5px 0;\"\u003e\u003ca href=\"\/blogs\/guides\/best-carbon-monoxide-detector-2026\" style=\"color:#4fc3f7;text-decoration:underline;\"\u003ebest carbon monoxide detector 2026\u003c\/a\u003e\u003c\/li\u003e\n\u003cli style=\"margin:5px 0;\"\u003e\u003ca href=\"\/blogs\/guides\/best-smoke-detectors-2026\" style=\"color:#4fc3f7;text-decoration:underline;\"\u003ebest smoke detectors 2026\u003c\/a\u003e\u003c\/li\u003e\n\u003cli style=\"margin:5px 0;\"\u003e\u003ca href=\"\/products\/first-alert-gco1-combination-carbon-monoxide-and-explosive-gas-alarm\" style=\"color:#4fc3f7;text-decoration:underline;\"\u003eFirst Alert GCO1 Combination Carbon Monoxide a\u003c\/a\u003e\u003c\/li\u003e\n\u003cli style=\"margin:5px 0;\"\u003e\u003ca href=\"\/products\/first-alert-co710-10-year-sealed-battery-carbon-monoxide-alarm-with-digital-display\" style=\"color:#4fc3f7;text-decoration:underline;\"\u003eFirst Alert CO710 10-Year Sealed Battery Carbo\u003c\/a\u003e\u003c\/li\u003e\n\u003cli style=\"margin:5px 0;\"\u003e\u003ca href=\"\/products\/first-alert-co615-plug-in-carbon-monoxide-alarm-with-battery-backup-and-digital-display\" style=\"color:#4fc3f7;text-decoration:underline;\"\u003eFirst Alert CO615 Plug-In Carbon Monoxide Alar\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e","brand":"First Alert","offers":[{"title":"Default Title","offer_id":44089212960856,"sku":null,"price":0.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0594\/1900\/0920\/files\/31xKO7zoB2L._SL500_57945a71-065b-4881-b18a-6eedb14ff9d8.jpg?v=1778350245"},{"product_id":"first-alert-co600-plug-in-ac-powered-carbon-monoxide-alarm","title":"First Alert CO600 Plug-In AC-Powered Carbon Monoxide Alarm","description":"\u003cp\u003e\u003cstrong\u003eShort answer:\u003c\/strong\u003e The CO600 is First Alert's plug-in AC-powered CO alarm — permanent, no battery maintenance, designed for locations with a reliable outlet. The tradeoff versus the CO606 is that the CO600 has no battery backup, meaning a power outage during a CO event would cut power to the alarm. For most permanent home installations where power outages are infrequent, the CO600 is solid. For peace of mind during outages, step up to the CO606.\u003c\/p\u003e\n\n\u003cdiv style=\"background:#1a1a1a;border-left:4px solid #ff9800;border-radius:4px;padding:16px 20px;margin:24px 0;\"\u003e\n\u003cstrong style=\"color:#ff9800;\"\u003eKey specs at a glance\u003c\/strong\u003e\n\u003cul style=\"margin-top:10px;padding-left:18px;line-height:2;color:#e0e0e0;\"\u003e\n\u003cli\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003ePower:\u003c\/strong\u003e 120V AC plug-in — no batteries required\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eBattery Backup:\u003c\/strong\u003e None\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eSensor:\u003c\/strong\u003e Electrochemical CO sensor\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eAlarm Output:\u003c\/strong\u003e 85dB at 10 feet\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eEnd-of-Life Signal:\u003c\/strong\u003e Yes — audible warning when replacement is needed\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eListing:\u003c\/strong\u003e UL 2034\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eWarranty:\u003c\/strong\u003e 7-year limited\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eDimensions:\u003c\/strong\u003e 5\" × 3.4\" × 1.7\"\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eCO600 vs CO606 — Do You Need Battery Backup?\u003c\/h2\u003e\n\u003ctable style=\"width:100%;border-collapse:collapse;background:#1a1a1a;color:#e0e0e0;margin:16px 0;font-size:0.9em;\"\u003e\n\u003cthead\u003e\u003ctr style=\"background:#2a2a2a;\"\u003e\n\u003cth style=\"padding:10px 12px;border:1px solid #333;color:#ffb74d;text-align:left;\"\u003eScenario\u003c\/th\u003e\n\u003cth style=\"padding:10px 12px;border:1px solid #333;color:#ffb74d;text-align:center;\"\u003eCO600\u003c\/th\u003e\n\u003cth style=\"padding:10px 12px;border:1px solid #333;color:#ffb74d;text-align:center;\"\u003eCO606\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;\"\u003eNormal operation (AC power on)\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;text-align:center;\"\u003e✓ Full function\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;text-align:center;\"\u003e✓ Full function\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#222;\"\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;\"\u003ePower outage\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;text-align:center;\"\u003e✗ No protection\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;text-align:center;\"\u003e✓ Battery takes over\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;\"\u003eBattery maintenance\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;text-align:center;\"\u003eNone required\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;text-align:center;\"\u003eAnnual 9V replacement\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#222;\"\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;\"\u003eCO risk during outages\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;text-align:center;\"\u003eHigher (generators, candles)\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;text-align:center;\"\u003eCovered\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;\"\u003ePrice point\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;text-align:center;\"\u003eLower\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #333;text-align:center;\"\u003eHigher\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eCO Poisoning Risk and Why Placement Matters\u003c\/h2\u003e\n\u003cp\u003eCarbon monoxide is produced by any fuel-burning appliance — gas furnaces, water heaters, generators, fireplaces, and vehicle exhaust. CO is colorless and odorless and at moderate concentrations causes symptoms that mimic the flu: headache, dizziness, nausea. At high concentrations it causes loss of consciousness and death. The CO600 is rated to alarm before CO reaches dangerous concentration levels in normal residential exposure scenarios.\u003c\/p\u003e\n\n\u003cul style=\"line-height:2;color:#e0e0e0;padding-left:18px;\"\u003e\n\u003cli\u003eInstall on each level of the home and outside each sleeping area\u003c\/li\u003e\n\u003cli\u003ePlace 5 feet above floor level — CO is slightly lighter than air and disperses throughout the room\u003c\/li\u003e\n\u003cli\u003eAvoid kitchens, high-humidity areas, and locations near furnace vents\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003ch4\u003eWill the CO600 work during a power outage?\u003c\/h4\u003e\n\u003cp\u003eNo — the CO600 requires 120V AC and has no battery backup. During a power outage, the unit will not function. This is a critical consideration because power outages often coincide with increased CO risk from generators and alternative heating sources. If outage protection is important, choose the CO606 instead.\u003c\/p\u003e\n\n\u003ch4\u003eDoes the CO600 detect smoke or natural gas?\u003c\/h4\u003e\n\u003cp\u003eNo — the CO600 detects carbon monoxide only. It will not alarm for smoke, propane, natural gas, or other hazards. Install separate smoke alarms and consider a natural gas\/propane detector if applicable.\u003c\/p\u003e\n\n\u003ch4\u003eHow long does the CO600 last?\u003c\/h4\u003e\n\u003cp\u003eFirst Alert rates the CO600 for a 7-year service life. The electrochemical sensor degrades over time and the unit emits an end-of-life signal (distinct from the alarm pattern) when replacement is needed. Do not attempt to extend use beyond the rated service life.\u003c\/p\u003e\n\n\u003ch4\u003eIs the CO600 sufficient to meet code requirements?\u003c\/h4\u003e\n\u003cp\u003eThe CO600 is UL 2034 listed, which is the standard referenced by NFPA 720 and most state CO alarm codes. However, check local requirements — some jurisdictions require battery backup or interconnected alarms in new construction.\u003c\/p\u003e\u003c!--wcs-deorphan-all-v1--\u003e\u003cdiv style=\"background:#1a2733;border-left:4px solid #ffb74d;border-radius:8px;padding:14px 18px;margin:20px 0;color:#e0e0e0;\"\u003e\n\u003cstrong style=\"color:#ffb74d;\"\u003eRelated Products \u0026amp; Guides\u003c\/strong\u003e\u003cul style=\"padding-left:20px;margin:8px 0 0;\"\u003e\n\u003cli style=\"margin:5px 0;\"\u003e\u003ca href=\"\/collections\/co-detectors\" style=\"color:#4fc3f7;text-decoration:underline;\"\u003eco detectors\u003c\/a\u003e\u003c\/li\u003e\n\u003cli style=\"margin:5px 0;\"\u003e\u003ca href=\"\/collections\/first-alert-carbon-monoxide-alarms-detectors\" style=\"color:#4fc3f7;text-decoration:underline;\"\u003efirst alert carbon monoxide alarms detectors\u003c\/a\u003e\u003c\/li\u003e\n\u003cli style=\"margin:5px 0;\"\u003e\u003ca href=\"\/collections\/home-safety\" style=\"color:#4fc3f7;text-decoration:underline;\"\u003ehome safety\u003c\/a\u003e\u003c\/li\u003e\n\u003cli style=\"margin:5px 0;\"\u003e\u003ca href=\"\/blogs\/guides\/best-carbon-monoxide-detector-2026\" style=\"color:#4fc3f7;text-decoration:underline;\"\u003ebest carbon monoxide detector 2026\u003c\/a\u003e\u003c\/li\u003e\n\u003cli style=\"margin:5px 0;\"\u003e\u003ca href=\"\/blogs\/guides\/best-smoke-detectors-2026\" style=\"color:#4fc3f7;text-decoration:underline;\"\u003ebest smoke detectors 2026\u003c\/a\u003e\u003c\/li\u003e\n\u003cli style=\"margin:5px 0;\"\u003e\u003ca href=\"\/products\/first-alert-gco1-combination-carbon-monoxide-and-explosive-gas-alarm\" style=\"color:#4fc3f7;text-decoration:underline;\"\u003eFirst Alert GCO1 Combination Carbon Monoxide a\u003c\/a\u003e\u003c\/li\u003e\n\u003cli style=\"margin:5px 0;\"\u003e\u003ca href=\"\/products\/first-alert-co710-10-year-sealed-battery-carbon-monoxide-alarm-with-digital-display\" style=\"color:#4fc3f7;text-decoration:underline;\"\u003eFirst Alert CO710 10-Year Sealed Battery Carbo\u003c\/a\u003e\u003c\/li\u003e\n\u003cli style=\"margin:5px 0;\"\u003e\u003ca href=\"\/products\/first-alert-co615-plug-in-carbon-monoxide-alarm-with-battery-backup-and-digital-display\" style=\"color:#4fc3f7;text-decoration:underline;\"\u003eFirst Alert CO615 Plug-In Carbon Monoxide Alar\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e","brand":"First Alert","offers":[{"title":"Default Title","offer_id":44089213059160,"sku":null,"price":0.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0594\/1900\/0920\/files\/31hRIkupCLL._SL500.jpg?v=1778350252"},{"product_id":"first-alert-co250-battery-carbon-monoxide-alarm-with-tamper-resistant-cover","title":"First Alert CO250 Battery Carbon Monoxide Alarm with Tamper-Resistant Cover","description":"\u003cp\u003eThe \u003cstrong\u003eFirst Alert CO250 Battery-Powered Carbon Monoxide Alarm with Tamper-Resistant Cover\u003c\/strong\u003e is designed for both residential and commercial environments where security and reliability are essential. The locking cover prevents accidental battery removal or tampering.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eTamper-resistant cover with lock helps prevent unauthorized removal of battery\u003c\/li\u003e\n\u003cli\u003eDual silence modes: alarm silence and peak level memory silence\u003c\/li\u003e\n\u003cli\u003ePowered by 1 standard 9-volt battery\u003c\/li\u003e\n\u003cli\u003eLoud 85dB alarm for clear household audible alert\u003c\/li\u003e\n\u003cli\u003e7-year limited warranty\u003c\/li\u003e\n\u003cli\u003eDimensions: 4.25\" x 4.25\" x 1.6\"\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eSuitable for rental properties, dormitories, and any setting where alarm integrity must be maintained. Meets UL 2034 safety standards.\u003c\/p\u003e","brand":"First Alert","offers":[{"title":"Default Title","offer_id":44089213091928,"sku":null,"price":0.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0594\/1900\/0920\/files\/41vdr1DzhYL._SL500.jpg?v=1778350259"}],"url":"https:\/\/wcsafety.com\/collections\/first-alert-carbon-monoxide-alarms-detectors.oembed","provider":"WC Safety","version":"1.0","type":"link"}