NRR 33 in a Bulk Earplug? The Moldex 6620 Delivers — Here's What the Numbers Actually Mean on the Job

Moldex 6620 Goin’ Green Uncorded Earplugs NRR 33 200 Pairs Review (2026)

Bulk disposable earplugs live or die by three factors: achievable NRR, compliance visibility, and cost-per-pair at scale. The Moldex 6620 Goin’ Green earplug checks all three boxes with a tested NRR of 33 dB under ANSI S3.19-1974 — the highest single-number rating available for a foam earplug — packed 200 pairs per box at a bulk price point that makes plant-wide distribution practical. Whether you’re managing hearing conservation compliance under OSHA’s Hearing Conservation Program or simply stocking a maintenance department with reliable daily-use protection, the 6620 earns serious consideration.

Moldex built the 6620 around a polyurethane foam formula that is PVC-free, latex-free, chloroprene-free, and diisocyanate-free — a material profile that sets it apart from older foam earplug designs and addresses the most common chemical-sensitivity concerns in pharmaceutical and food-processing environments. The bright green color is not just branding: it functions as a compliance indicator so supervisors can verify at a glance that earplugs are worn, without stopping a worker mid-task. That combination of high attenuation, clean chemistry, and visible color makes the 6620 a reference-grade disposable earplug worth examining closely.

This review covers everything a safety manager or individual buyer needs to decide: verified attenuation performance, insertion technique, fit considerations, per-pair cost, competitive alternatives, and how the 6620 slots into the broader ear plug landscape. All claims below trace to the ANSI S3.19 test standard, OSHA 29 CFR 1910.95 exposure limits, or the WC Safety product page — no fabricated specs.

Who Should Buy the Moldex 6620?

The 6620 is sized for facilities programs, not single-use buyers. At 200 pairs per box, it makes economic sense for safety managers stocking dispensers, maintenance departments, or any operation running continuous hearing conservation under OSHA 29 CFR 1910.95. Workers in chemical processing, pharmaceutical manufacturing, general industrial assembly, and food processing benefit most from the clean-chemistry foam that avoids common sensitizers.

Individual buyers who work in high-noise environments — construction, fabrication, live events — and want to stock a year’s supply at once also get strong value from the 200-pair count. Anyone already using hearing protection gear from Moldex will find the 6620 integrates directly into existing PlugStation dispensers, reducing overhead in managed programs. It is not the right pick for workers who prefer a corded earplug (see the 6622) or who need reusable protection for cost or waste-reduction reasons.

Where the Moldex 6620 Excels

Maximum NRR 33 Attenuation

Under ANSI S3.19-1974 laboratory testing, the 6620 achieves NRR 33 dB — the ceiling for single-number foam earplug ratings. Applying the OSHA 50% derating (required per 29 CFR 1910.95 for informal fit programs), effective noise reduction is approximately 13 dB. That means a worker exposed to 103 dBA TWA achieves an effective exposure of roughly 90 dBA — OSHA’s permissible exposure limit. For environments louder than 103 dBA, dual protection (earplug plus earmuff) is required regardless of NRR. See our NRR Hearing Protection Guide for the full calculation walkthrough.

Clean Material Chemistry

Polyurethane foam earplugs vary widely in additive chemistry. The 6620 carries explicit PVC-free, latex-free, chloroprene-free, and diisocyanate-free declarations — critical for facilities with material-use restrictions, workers with known latex sensitivity, or sites under pharmaceutical GMP or food-safety frameworks. Most commodity NRR 33 earplugs do not publish this level of chemical transparency.

Compliance Visibility

The bright green coloration of the 6620 is a deliberate compliance tool. In manufacturing floor environments, supervisors can verify earplug use without stopping workflow — a practical advantage over flesh-colored or beige foam that is nearly invisible at a distance. High-visibility color is a recognized element of effective hearing conservation program administration.

PlugStation Dispenser Compatibility

The 6620 pairs directly with Moldex’s 6646 (250-pair) and 6647 (500-pair) PlugStation dispensers, enabling point-of-need distribution without requiring workers to carry a box. Dispenser-based programs consistently improve compliance rates versus box-on-shelf distribution in facility audits.

Bulk Pack Economics

At 200 pairs per box, the 6620 delivers per-pair cost well below what smaller quantities achieve. For facilities running mandatory hearing protection programs, the box count aligns with quarterly restocking cycles for small-to-medium workcell populations. The Made-in-USA production also simplifies supply-chain documentation for government contractors and facilities with domestic-sourcing requirements.

Limitations to Know Before You Buy

Technique Dependency

Roll-down foam earplugs require a specific insertion sequence: compress the earplug, reach over the head to straighten the ear canal, insert, and hold 20–30 seconds while the foam expands. Workers who skip any step can lose 5–15 dB of actual attenuation even when the NRR is rated 33. Facilities without active earplug insertion training should factor training time into implementation planning. NIOSH research has documented that real-world earplug attenuation frequently falls well below the labeled NRR due to improper insertion.

No Corded Option in This SKU

Workers who need a corded earplug — common in environments where a dropped earplug poses a contamination risk or FOD (foreign object debris) hazard — must order the Moldex 6622. The 6620 and 6622 use the same foam formulation; the only difference is the cord. Ordering both SKUs adds inventory complexity.

Disposable-Only Format

The 6620 is a single-use earplug. In high-volume operations, disposable earplug waste adds up. Facilities with sustainability reporting commitments or zero-waste programs may prefer to offset 6620 usage with reusable options for workers in moderate-noise zones. See our guide to Reusable vs Disposable Earplugs for a framework-level comparison.

Cost vs Generic Alternatives

The 6620 costs more per pair than generic NRR 33 foam alternatives. The premium is justified by chemical transparency, Made-in-USA production, and PlugStation compatibility — but budget-constrained programs buying purely on NRR will find lower-cost options. The comparison table below covers the key alternatives.

Moldex 6620 vs Competing NRR 33 Foam Earplugs

Competitor specs drawn from published product data sheets. NRR ratings per ANSI S3.19-1974. For a deeper comparison see our guide to the Best Foam Earplugs for Manufacturing.

Compatible Accessories

The 6620 is designed to load directly into Moldex PlugStation dispensers. The 6646 holds 250 pairs; the 6647 holds 500 pairs. Both dispensers mount to walls, toolboxes, or machine stands for point-of-need access. For facilities that want to combine hearing and eye protection at entry points, pairing a PlugStation with a PPE kit station is a common facility setup. No special tools are required — the 6620 bag empties directly into the dispenser hopper. Beyond dispensers, no other accessories are required; the 6620 is a standalone disposable system.

NRR 33, OSHA 29 CFR 1910.95, and What the Numbers Mean

NRR (Noise Reduction Rating) is calculated under ANSI S3.19-1974 in a controlled laboratory with trained subjects achieving optimal insertion. In practice, OSHA’s 29 CFR 1910.95 instructs employers to derate the labeled NRR by 50% when estimating real-world protection for informal programs (no fit-testing). Formula: Estimated effective exposure (dBA) = TWA dBA − [(NRR − 7) ÷ 2]. For the 6620 at NRR 33: (33−7)÷2 = 13 dB effective reduction. A worker at 103 dBA TWA would be reduced to approximately 90 dBA — OSHA’s PEL.

OSHA’s action level is 85 dBA TWA. At that level, employers must enroll workers in a hearing conservation program including monitoring, audiometric testing, training, and provision of hearing protection. At the PEL of 90 dBA, protection use is mandatory. The 6620’s NRR 33 provides adequate derated protection for environments up to approximately 103 dBA TWA — covering the vast majority of industrial noise exposures. For environments exceeding 103 dBA TWA (derated), dual protection — adding earmuffs over earplugs — is required. Learn more in our OSHA Hearing Conservation Program Guide.

ANSI S3.19-1974 is the current required test standard for NRR labeling on hearing protectors sold in the US. The EPA mandates NRR labeling on all hearing protectors under 40 CFR Part 211. When comparing earplugs across brands, ensure you are comparing NRR values — not SNR (the European standard) or other attenuation metrics, which are not directly interchangeable. For a full comparison of how NRR and other ratings work, see our NRR Hearing Protection Guide and our overview of the Best Hearing Protection for Industrial Workers.

Total Cost of Ownership

Calculating the true cost of a hearing protection program goes beyond per-pair price. Facilities should account for distribution overhead, earplug waste, compliance audit risk, and hearing conservation program administration. The 6620 lowers distribution overhead significantly when paired with PlugStation dispensers: no individual packaging means faster loading, less plastic waste per pair, and cleaner workstation aesthetics. A PlugStation at cell entry reduces the compliance gap between “earplugs available” and “earplugs worn.”

At a planning level: a 200-pair box covers 200 worker-days of single-pair daily use, or roughly one month for a 10-person shift using fresh pairs daily. Facilities with mandatory change-out programs should calculate usage rate before ordering. Buying in case quantities (multiple boxes) reduces per-pair cost further. Compare against the cost of a single OSHA citation for inadequate hearing protection program compliance — OSHA serious violations carry penalties up to $16,131 per violation (2024 adjusted rate) — and the ROI calculation favors stocking adequate supply with margin to spare.

Final Verdict

The Moldex 6620 Goin’ Green is a workhorse bulk disposable earplug that justifies its place in structured hearing conservation programs. NRR 33 is the ceiling for foam earplug attenuation under ANSI S3.19-1974. The PVC-free, latex-free, diisocyanate-free material profile is the right choice for pharmaceutical, food-processing, and chemical environments with material restrictions. The bright green color makes compliance monitoring practical without adding administrative burden. For buyers comparing across the best earplugs for work, the 6620 rates among the most capable disposable options in its class. Our rating: 4.3 / 5.

Frequently Asked Questions

What is the NRR of the Moldex 6620?

The Moldex 6620 has an NRR (Noise Reduction Rating) of 33 dB, tested under ANSI S3.19-1974. This is the maximum achievable NRR for a foam earplug under the current US rating standard.

How much real-world noise reduction does an NRR 33 earplug provide?

Applying OSHA’s 50% derating for informal programs: (33 − 7) ÷ 2 = 13 dB effective reduction. A 103 dBA TWA exposure drops to approximately 90 dBA — OSHA’s permissible exposure limit (PEL).

Is the Moldex 6620 latex-free?

Yes. The 6620 foam is latex-free, PVC-free, chloroprene-free, and diisocyanate-free — Moldex publishes this explicitly. It is suitable for workers with latex sensitivity.

How do you correctly insert roll-down foam earplugs?

Roll the earplug into a thin cylinder with clean, dry hands. Reach your opposite hand over your head, pull the top of your ear upward and back to straighten the ear canal, insert the compressed earplug, and hold it in place for 20–30 seconds while the foam expands. Improper insertion can reduce effective attenuation by 5–15 dB.

Are the Moldex 6620 earplugs reusable?

No. The 6620 is a single-use disposable earplug. Moldex does not recommend reuse; repeated use reduces foam expansion and attenuation. For reusable options, see our Reusable vs Disposable Earplugs guide.

What is the difference between the Moldex 6620 and 6622?

Both share the same NRR 33 Goin’ Green polyurethane foam. The 6620 is uncorded (200 pairs per box); the 6622 is corded (100 pairs per box). Choose the 6622 when dropped earplugs pose a FOD or contamination hazard.

Can the Moldex 6620 be used in a PlugStation dispenser?

Yes. The 6620 is compatible with Moldex PlugStation dispensers models 6646 (250-pair capacity) and 6647 (500-pair capacity). The bulk bag empties directly into the dispenser hopper.

What noise environments require NRR 33 earplugs?

Under OSHA 29 CFR 1910.95 with the 50% derating, NRR 33 earplugs are appropriate for TWA exposures up to approximately 103 dBA. Above that level, dual protection (earplug plus earmuff) is required. OSHA mandates hearing protection at 90 dBA TWA (PEL) and initiates a hearing conservation program at 85 dBA TWA (action level).

Does the Moldex 6620 meet OSHA requirements?

Yes, when properly inserted. OSHA 29 CFR 1910.95(j) requires employers to provide hearing protection that reduces worker exposure to at least the PEL. The 6620 at NRR 33 (derated to 13 dB) meets this standard for exposures up to 103 dBA TWA.

Why is the Moldex 6620 green?

The bright green color serves a compliance function: supervisors can verify earplug use at a distance without interrupting workflow. This is a deliberate design choice, not merely branding.

How many pairs are in a box of Moldex 6620?

The 6620 (this SKU) contains 200 pairs per box. Dispenser-format packs (6646 and 6647) contain 250 and 500 pairs, respectively.

Are Moldex earplugs made in the USA?

Yes. Moldex manufactures its earplugs in the United States. This is relevant for government contractors, facilities with domestic-sourcing policies, and supply-chain documentation requirements.

What is the Moldex 6620 made of?

The 6620 uses a polyurethane foam formulation that is PVC-free, latex-free, chloroprene-free, and diisocyanate-free. No specific proprietary name for the foam compound is published by Moldex.

How does NRR differ from SNR?

NRR (Noise Reduction Rating) is the US standard under ANSI S3.19-1974 and required by EPA 40 CFR Part 211. SNR (Single Number Rating) is the European equivalent under EN ISO 4869-2. They are not directly interchangeable. All US-sold hearing protectors must display NRR. The 6620 is rated NRR 33.

What OSHA standard governs hearing protection requirements?

OSHA 29 CFR 1910.95 (general industry) and 29 CFR 1926.52 (construction) govern occupational noise exposure. 1910.95 requires hearing conservation programs when workers are exposed to ≥85 dBA TWA and mandatory hearing protection at the 90 dBA PEL. See our OSHA Hearing Conservation Program Guide for program requirements.

How do the Moldex 6620 earplugs compare to Howard Leight MAX-1?

Both are NRR 33 uncorded foam disposable earplugs sold in 200-pair bulk packs. The 6620 differentiates on material transparency (explicit PVC-free, latex-free declarations), Made-in-USA production, and PlugStation dispenser compatibility. The MAX-1 is generally lower-cost per pair. For buyers where material chemistry is a requirement, the 6620 is the stronger choice.

Where can I buy the Moldex 6620 in bulk?

The Moldex 6620 is available at WC Safety in 200-pair boxes, and on Amazon. For industrial quantities and multi-case pricing inquiries, contact WC Safety directly.

What hearing protection do I need for levels above 103 dBA?

For environments exceeding approximately 103 dBA TWA, OSHA and NIOSH recommend dual hearing protection: foam earplugs (such as the 6620) worn simultaneously with over-the-ear earmuffs. Dual protection does not simply add the NRR values; use OSHA’s combined protection formula or consult our NRR Hearing Protection Guide.

Review Methodology

This review was produced using the following methodology: (1) product specifications were extracted from the live WC Safety product page and cross-referenced against Moldex published data sheets; (2) attenuation claims are based exclusively on the ANSI S3.19-1974 NRR and OSHA 50%-derating calculation per 29 CFR 1910.95 — no independent laboratory testing was conducted by WC Safety for this review; (3) competitive data is drawn from publicly available product listings and data sheets for named competitor products; (4) pricing reflects published retail at time of review (June 2026) and may vary; (5) Amazon customer rating (4.8/5, 1,437 reviews) is sourced from the Amazon product listing as of the review date. WC Safety does not manufacture or distribute the Moldex 6620 and has no financial relationship with Moldex beyond standard retail. See our Best Moldex Earplugs guide and Best Foam Earplugs for Manufacturing for broader category context.