Moldex 2310N99 Disposable Particulate Respirator — Exhale Valve

The Moldex 2310N99 Disposable Particulate Respirator is a NIOSH-approved N99 disposable particulate respirator with integrated exhalation valve — providing 99% minimum filtration efficiency in a cup-style respirator packaged 10 per box in the Med/Large size for industrial and construction operations requiring filtration efficiency above the N95 95% threshold but for environments where the N100 99.97% level represents excess protection, or where N99 is specified by industrial hygiene assessment as the appropriate tier for the specific particulate exposure and protection factor requirement. The N99 rating occupies the middle tier in the NIOSH non-oil disposable respirator classification — above N95 at 95% minimum efficiency and below N100 at 99.97% — providing 99% minimum efficiency against non-oily airborne particles with the N (not oil-resistant) designation indicating certification without oil-based aerosol testing. The integrated exhalation valve reduces facepiece heat and moisture accumulation during physical work, directing exhaled air out of the cup rather than back through the filter media, improving wearing comfort during moderate and strenuous physical activity in warm working conditions.

Moldex 2310 N99 Respirator — Key Features

• NIOSH N99 — 99% minimum filtration efficiency, non-oil-resistant
• Exhalation valve — reduces facepiece heat and humidity during physical work
• Cup-style design — maintains facepiece volume for reduced filter contact and improved comfort
• Med/Large size, 10/box
• NIOSH Approved

Specifications

N99 in the NIOSH Efficiency Tier

NIOSH rates disposable particulate respirators in three efficiency tiers: 95% (N95/R95/P95), 99% (N99/R99/P99), and 99.97% (N100/R100/P100). The N99 2310 provides the middle efficiency tier — 99% minimum — in the non-oil-resistant classification. The 4 percentage points between N95 and N99 represent a meaningful difference in residual penetration: N95 allows up to 5% penetration while N99 allows up to 1% — N99 reduces residual particle penetration to one-fifth of the N95 maximum. For operations where the industrial hygiene assessment indicates that N95 protection factors are insufficient for the specific airborne concentration and hazard but where N100 would represent a materially more conservative specification than required, N99 provides the intermediate protection level. Certain hazardous substance exposure programs specify N99 as the minimum filtration for specific operations based on the calculated protection factors needed for the measured airborne concentrations and the relevant occupational exposure limits.

Exhalation Valve Comfort for Physical Industrial Work

The integrated exhalation valve is a one-way valve that opens during exhalation to direct exhaled air directly out of the facepiece rather than through the filter media. Cup-style respirators maintain an air space between the filter and the face, which accumulates heat and humidity from exhaled breath during continuous wear — particularly during physically demanding tasks where exhaled air volume and temperature are elevated. The valve redirects this exhaled air out of the cup, reducing the thermal and humidity burden on the filter and the wearer. Workers performing moderate to heavy physical work in warm environments — material handling, construction, maintenance operations — experience meaningfully better wearing comfort with valved respirators than with unvalved alternatives, which supports continuous wear throughout the shift rather than premature removal during heat discomfort events.

Compliance and Certifications

• NIOSH — N99 approved (42 CFR Part 84)
• OSHA 29 CFR 1910.134 — respiratory protection standard applies for mandatory use applications

Real-World Benefits

N99 99% filtration provides the intermediate efficiency tier for operations where N95 is insufficient and N100 is excessive. Industrial hygiene programs that have assessed specific hazardous substance exposures and determined that N95 protection factors are inadequate can specify N99 as the appropriate minimum efficiency without defaulting to the maximum N100 tier when the exposure calculations do not require it.

Exhalation valve supports comfortable extended wear in physically demanding industrial operations. Workers performing material handling, construction, and maintenance tasks in warm environments maintain comfortable continuous respirator use throughout the shift with the exhalation valve reducing facepiece heat accumulation that motivates premature removal in unvalved alternatives.

10/box packaging matches the procurement density of standard industrial respiratory protection programs. Safety managers deploying N99 respirators for operations with daily or shift-change replacement protocols manage procurement at standard industrial quantities with the 10/box format, consistent with the per-shift disposable programs used for N95 and other disposable respirator deployments.

Applications and Use Cases

• Intermediate-hazard particulate operations where N95 is insufficient — N99 for operations where industrial hygiene assessment indicates N95 protection factors do not achieve required margins for specific airborne concentrations and exposure limits
• High-hazard non-oily dust in physically demanding work environments — N99 with valve for workers performing active physical work in dust-generating operations requiring filtration above the N95 level
• Regulatory or program-specified N99 minimum — for hazardous substance programs that specify N99 as the minimum filtration tier for specific operations based on calculated protection factor requirements

Related Products

For N100 99.97% maximum filtration, see Moldex 4700N100 AirWave N100 Respirator — SmartStrap + Valve. For R95 oil-resistant with valve, see Moldex 2740R95 HandyStrap R95 Disposable Particulate Respirator. Browse the complete Respiratory Protection collection.

Frequently Asked Questions

When is N99 specified instead of N95 or N100?

N99 is specified when a quantitative assessment of the airborne hazard — measured concentration, occupational exposure limit, required protection factor — indicates that N95 provides insufficient margin for the specific exposure scenario, but N100 provides more efficiency than the hazard requires. This determination requires industrial hygiene analysis; the specification should be based on calculated protection factor needs, not on a general preference for "more protection." Consult a certified industrial hygienist (CIH) for respiratory protection program specification when the appropriate efficiency tier is not clear from OSHA's standard table of assigned protection factors and measured airborne concentrations.

Can the 2310N99 be used in environments with oil-based aerosols?

No. N-rated respirators are not appropriate for environments containing oil-based aerosols, oil mist, or oil-containing particulates. The N99 rating certifies efficiency against non-oily particles only; oil-based aerosols can coat N-rated filter fibers and degrade efficiency below the rated minimum. For environments with oil-based aerosols, R99 or P99 oil-resistant ratings are required. If there is any uncertainty about oil content in the airborne hazard, use the appropriate oil-resistant (R or P) rated respirator.