Only One Operator Exceeds 90 dBA: Is a Hearing Conservation Program Needed?
Granite Spring Bottling produces 12-ounce glass bottles on three filling lines. A recent dosimetry survey produced these full-shift results: filler operator 91 dBA 8-hour TWA; case packer 86 dBA; quality-control technician 83 dBA; maintenance mechanic 89 dBA, with repeated impact peaks measured at 128 dB. Filler operators work 12-hour shifts, and the dosimeter results were already normalized to eight hours. The plant's only response to date has been to hand out foam earplugs to anyone who asks. No audiograms have been given, no noise training has been conducted, and the plant has no written hearing conservation program. The plant manager argues that because only one operator exceeds the 90 dBA limit, engineering controls are unnecessary and hearing protection is enough. The maintenance mechanic has asked why he is not included in anything, since his exposure is under 90.
1. Who must be included in a hearing conservation program, and what does 1910.95(c) require the plant to have in place?
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The trigger for the hearing conservation program is 85 dBA as an 8-hour time-weighted average, not 90. Under 1910.95(c), the program is required whenever employee noise exposures equal or exceed that level, so the filler operator (91), the maintenance mechanic (89), and the case packer (86) are all covered. The quality-control technician at 83 falls below the action level and is not automatically included - but the employer should confirm the sample is representative, because intermittent visits to the filling lines could push her over on another day, and monitoring must be repeated whenever production changes increase exposure.
The program must include (c)(1): monitoring and accurate exposure records; audiometric testing; hearing protectors provided at no cost to employees exposed at or above 85 dBA; employee training; and recordkeeping. Baseline audiograms are due within six months of an employee's first exposure (1910.95(g)(5)), annual audiograms thereafter under (g)(7), training annually under (k), and records kept as required by (m) - noise exposure records for two years, audiometric records for the duration of employment.
The mechanic's question deserves a direct answer: 89 dBA is above the action level, so he is in the program and gets a baseline audiogram, annual training, and free protectors even though he is below the 90 dBA PEL.
2. The manager wants to rely only on earplugs for the 91 dBA filler operator. Is that permissible, and what must the employer do about engineering controls?
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No. 1910.95(b)(1) requires feasible engineering or administrative controls whenever employee noise exposures exceed the 90 dBA 8-hour TWA, and permits hearing protectors only when those controls are not feasible or while they are being implemented. Where the controls are being implemented, protectors must be worn until the controls achieve compliance. So the filler operator at 91 dBA does not get to be a permanent earplug-only solution.
The employer owes a documented feasibility analysis, not an assertion. Practically that means an acoustic survey identifying dominant sources on the filling lines - bottle-to-bottle contact, conveyor transfers, worn chains and guides, motors, air nozzles - and evaluating controls such as replacing metal guide rails with quieter materials, slowing or re-routing transfer points, enclosures and silencers, and a preventive maintenance program for worn parts. Cost and technical feasibility both count, and small exceedances are still exceedances.
The mechanic at 89 dBA is below the PEL, so engineering controls are not required for him, but he remains in the hearing conservation program because he is above 85. His 128 dB impact peaks also deserve attention: impulse noise drives hearing loss differently from steady noise and may warrant a separate look at the equipment generating the impacts.
3. Twelve years into the job, a filler operator's annual audiogram shows a 15 dB average shift at 2000, 3000, and 4000 Hz in the right ear. What does 1910.95 require the employer to do with that result?
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First classify it: a standard threshold shift under 1910.95(g)(10)(i) is an average shift of 10 dB or more at 2000, 3000, and 4000 Hz in either ear, so 15 dB qualifies. The shift must be confirmed and its cause evaluated.
Required actions, in sequence:
- Follow-up audiogram within 30 days under (g)(8), which may be preceded by a retest within 30 days to rule out a temporary shift from recent exposure.
- Professional determination: a physician or audiologist must determine whether the shift is work-related or aggravated by occupational noise, and whether it is persistent (g)(9). The employer does not make that call alone.
- Protection and training: if the shift is work-related, refit and retrain on hearing protectors, and verify attenuation against the measured exposure using the NRR with the required adjustment; consider moving the employee to lower-exposure work.
- Recording evaluation: a confirmed, work-related standard threshold shift may be a recordable illness under 1904.5 and 1904.7. Do not log it automatically; evaluate work-relatedness and whether it meets the criteria.
- Baseline revision: if the shift is persistent and not work-related, the baseline may be revised, which affects how future shifts are measured.
The 12-year tenure matters: this employee's lifetime exposure is the strongest argument for actually implementing the engineering controls the plant has been deferring.