Noise Exposure and Hearing Exposure

There are three ways to nip the noise issues in the bud at your plant.

By Chris E. Marsh and Don R. Royer
Chris Marsh, who owns Ogeechee Training Service in Statesboro, Ga., helps businesses come into compliance with OSHA regulations and also provides them with employee risk management services. Don Royer is the safety coordinator at Rotondo Precast, Oldcastle Inc., in Rehoboth, Mass.

As we age, hearing problems sometimes develop. This can be physiological, disease-related or work-related. The National Institute for Occupational Safety and Health (NIOSH), a unit of the U.S. Center for Disease Control, has named hearing loss one of the 21 priority areas for research in the next century. Noise-induced hearing loss is 100 percent preventable, but once acquired, hearing loss is permanent and irreversible. Therefore, preventive measures must be taken by employers and workers to ensure the protection of workers’ hearing.

NIOSH states that approximately 30 million U.S. workers are exposed to hazardous noise on the job. One could assume the percentage is similar in Canada, and in fact in British Columbia during the five-year period from 1994-1998, the workers’ compensation board paid $18 million in permanent disability awards to 3,207 workers suffering hearing loss.

Hearing loss develops slowly over a period of several years as the result of exposure to continuous or intermittent loud noise. Noise-induced hearing loss remains one of the most prevalent occupational conditions, partly because noise is one of the most pervasive occupational hazards found in a wide range of industries. OSHA has recognized this problem for many years and issued a standard (29 CFR 1910.95) specifically addressed to this area of concern.

OSHA states that the employer must set up and administer a hearing conservation program if the employee noise exposure is 85 decibels or more over an eight-hour time-weighted average (TWA). The cause could be a particular area of production caused by just one machine, or it could be caused by several different machines in different areas of the plant. The key is to measure the noise level wherever it exists. The areas where noise exists will vary from plant to plant.

If you do find that you have a hearing conservation problem, there are three ways you can address it. You may choose to diminish it through engineering controls. For example, you could find some way to muffle the noise or build an acoustic barrier that would funnel the noise in another direction.

Another suggestion is to modify work practices. Workers could be cross-trained so that no individual would have to be exposed to the noise for long periods of time. They could shift from one area of high noise exposure to an area with minimum noise exposure.

The third way to reduce exposure is to provide Personal Protective Equipment (PPE) for workers, such as ear plugs or ear muffs.

The employer’s hearing conservation program must include five elements: a monitoring program, hearing protection devices, employee training and education, recordkeeping and an audiometric testing program. This list comes from the OSHA compliance officer’s Technical Manual, which tells them what and how to inspect.

Monitoring program
The employer must develop a monitoring program whenever the information indicates that the employee’s exposure may equal or exceed the action level. The sampling strategy must be designed to identify all employees for inclusion that may be exposed and enable the proper selection of hearing protectors. The monitoring requirement is performance-based, as it allows employers to choose a monitoring method that best suits each individual work situation. Either personal or area monitoring may be used. Noise measurements must integrate all continuous, intermittent and impulsive noise levels from 80 to 130 decibels.

Repeated measuring must take place whenever a change in production, equipment or controls increase noise exposures to the extent that additional employees may be exposed at or above the action level, and/or the protection provided by hearing protectors used by employees may be rendered inadequate to meet the requirements of hearing protection devices (see next segment). The employer must notify each employee who is exposed at or above the action level of the results of the monitoring and must provide affected employees or their representatives with an opportunity to observe noise monitoring procedures.

Hearing protection devices
Hearing protection devices (HPDs) are considered the last option to control exposure to noise. They are generally used during the necessary time it takes to implement engineering or administrative controls, or when such controls are not feasible. (What OSHA is saying here is that you should engineer the noise out or set administrative controls before using hearing protection.)

Employers must make HPDs available to all employees exposed at or above the action level. These must be provided at no cost to employees and must be replaced as necessary. Employers must ensure that HPDs are worn by employees where feasible administrative and engineering controls fail to reduce sound levels or by employees who are exposed at or above the level, and who have not had a baseline audiogram established or have experienced a standard threshold shift. Employees must be given the opportunity to select their HPDs from a suitable variety. Generally, this should include a minimum of two devices representative of at least two different types. The employer must provide training in the use and care of all HPDs provided to employees and must ensure proper initial fitting of HPDs and supervise their correct use.

Attenuation refers to the damping or decrease of noise levels as a result of wearing HPDs. The employer must evaluate HPD attenuation for the specific noise environments in which they will be used. They must attenuate employee exposure to at least an eight-hour time-weighted average of 85 decibels. If a standard threshold shift has occurred, the exposure level must be at or below 85 decibels.

Employee training and education
The employer must institute a training program for all employees affected by noise exposure at or above the levels in this standard. Training must be repeated annually for each employee, and the employer must ensure employee participation. Information must be updated to be consistent with changes in protective equipment and with company processes. The employer must ensure that each employee is informed of the following:

• the effects of noise on hearing;
• the purpose of hearing protectors, the advantages, disadvantages and attenuation of various types, along with selection, fitting, use and care; and
• the purpose of audiometric testing and an explanation of test procedures.

The employer must make copies of the OSHA noise standard (29 CFR 1910.95) available to affected employees and post a copy in the workplace. You must provide affected employees with any informational materials pertaining to the standard that are supplied to the employer by OSHA, and provide upon request all material relating to the employer’s training and education program to OSHA.

Recordkeeping
Employers must maintain an accurate record of all employee exposure measurements and retain the records for two years. Retain all audiometric test records and include the name and job classification of the employee, date of the audiogram, the examiner’s name, the date of the last machine calibration and the employee’s most recent noise exposure assessment. Employers should also maintain accurate records of the background sound pressure level measurements in audiometric sound rooms and maintain these records for the duration of the affected worker’s employment.

All records required by this standard must be provided on request to the employee, former employees, representatives designated by the individual employee and OSHA.

Audiometric testing program
The employer must establish and maintain at no cost to employees an audiometric testing program by making testing available to all employees whose exposures equal or exceed 85 decibels in an eight-hour time-weighted average. The audiometric testing program must be performed by a competent, licensed professional and be first used to provide a baseline audiogram within six months of the employee’s first exposure to the above-mentioned action level. At least annually following the baseline audiogram, the employer will obtain another audiogram on any employee who meets the exposure level. The annual audiogram will be compared to the baseline to determine if any damage has been done. If there is a standard threshold shift, another audiogram must be completed within 30 days. A medical professional will compare audiograms to determine whether further testing is needed.

You should obtain a copy of this OSHA standard to read additional information concerning your obligations. In addition to the standard, there are nine appendixes included in the OSHA manual. Some of this is technical information and does not lend itself to discussion in an article of this length.

Consult with a local qualified medical provider for further insight and knowledge on this subject. A medical professional should definitely be involved (and must be in some situations) with meeting the requirements of this standard.