An effective hearing conservation program can prevent hearing loss, improve employee morale and a general feeling of well-being, increase quality of production, and reduce the incidence of stress-related disease. Employers must administer a continuing, effective hearing conservation program whenever employee noise exposures are at or above an eight hour time-weighted average (TWA) of 85 dBA or, equivalently, a dose of 50 percent. This is referred to as the action level.
Minimum requirements of a hearing conservation program include:
- Monitoring program,
- Audiometric testing program,
- Hearing protection devices,
- Employee training, and
- Recordkeeping.
Monitoring Program
Employers have to develop and implement a monitoring program whenever information indicates that any employee's exposure may equal or exceed the action level. The sampling strategy must be designed to identify all employees for inclusion in the hearing conservation program 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. If there are circumstances that may make area monitoring generally inappropriate, such as high worker mobility, significant variations in sound level or a significant component of impulse noise, then the employer must use representative personal sampling unless it can be shown that area sampling produces equivalent results.
Noise measurements must integrate all continuous, intermittent, and impulsive noise levels from 80 to 130 dBA. Monitoring must be repeated whenever a change in production, process, equipment or controls increases noise exposures to the extent that additional employees may be exposed at or above the action level, or the attenuation provided by hearing protectors used by employees is inadequate.
The employer must notify each employee who is exposed at or above the action level of the results of the monitoring and provide them with an opportunity to observe noise monitoring procedures.
Hearing Protection Devices (HPDs)
Hearing protection devices (HPDs) are considered the last option to control exposures to noise. HPDs are generally used during the necessary time it takes to implement engineering or administrative controls, or when such controls are not feasible.
Employers must make HPDs available at no cost to all employees exposed at or above the action level and provide replacements as necessary. Further, they must ensure that HPDs are worn by employees where feasible administrative and engineering controls fail to reduce sound levels within those listed in Table G-16, or who are exposed at or above the action level and who have not yet had a baseline audiogram established or have experienced a standard threshold shift (STS).
HPD Selection and Use
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 protectors provided to employees and ensure proper initial fitting and supervise their correct use.
HPD Attenuation
Attenuation refers to the damping or decrease of noise levels as a result of wearing HPDs. The employer has to evaluate HPD attenuation for the specific noise environments in which the HPD will be used. HPDs must attenuate employee exposure to at least an eight hour time-weighted average of 90 dBA.
For employees who have experienced a standard threshold shift (STS), HPDs must attenuate exposure at or below the action level of 85 dBA-TWA (time-weighted average). The adequacy of the HPDs must be reevaluated whenever employee noise exposures increase to the extent that they may no longer provide adequate attenuation. The employer must provide more effective hearing protectors as necessary.
Employee Training
OSHA requires employers to establish a training program for all employees with noise exposures at or above the action level and ensure employee participation. Training must be repeated annually for each employee in the hearing conservation program and the information must be updated to be consistent with changes in protective equipment and work 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, and instructions on selection, fitting, use, and care.
- The purpose of audiometric testing and an explanation of test procedures.
Access to Information and Training Materials
Employers have to make copies of the noise standard available to affected employees and post a copy in the workplace. They also are required to provide affected employees with any informational materials pertaining to the standard that are supplied to the employer by OSHA and give OSHA copies of all material relating to the employer's training and education program (on request).
Recordkeeping
OSHA has specific recordkeeping requirements for noise monitoring and employee testing results.
Exposure Measurements
Employers must maintain an accurate record of all employee exposure measurements. These records must be retained for two years.
Audiometric Test Records
The employer must retain all employee audiometric test records. These records must include:
- Name and job classification of the employee.
- Date of the audiogram.
- The examiner's name.
- Date of the last acoustic or exhaustive calibration of the audiometer.
- Employee's most recent noise exposure assessment.
Additionally, the employer has to maintain accurate records of the background sound pressure level measurements in audiometric test rooms. These records must be maintained for the duration of the affected worker's employment.
Access to Records
All records required by the noise standard must be provided upon request to employees, former employees, representatives designated by the individual employee, and OSHA.
Employers who cease to do business must transfer to the successor employer all records required by the noise standard. The successor employer has to retain these records for the remainder of the periods described previously.
Recording Hearing Loss on the 300 Log
Noise-induced hearing loss is a serious and irreversible condition. However, it is not the type of occupational injury that typically requires days away from work for recuperation. All work-related hearing losses of 10 decibel shifts that result in a total 25 decibel shift above audiometric zero have to be recorded on the 300 Log.
Audiometric Zero and STS
A standard threshold shift (STS) is a change in hearing threshold, relative to an employee's baseline audiogram (hearing test), averaging 10 decibels (dB) or more at 2,000, 3,000, and 4,000 hertz (Hz) in one or both ears. If an employee's audiogram reveals that a work-related STS has occurred in one or both ears, and the total hearing level is 25 decibels or more above audiometric zero in the same ear(s) as the STS, the case is recordable.
If you have an employee with a recordable STS, document the case by checking the "hearing loss" column (M)(5) on the OSHA 300 Log.
Retesting
Retesting allows you to exclude false positive results and temporary threshold shifts from the data. If you retest the employee's hearing within 30 days of the first test, and the retest does not confirm the STS, you are not required to record the hearing loss case on the OSHA 300 Log. However, if the retest confirms the STS, record the hearing loss illness within seven calendar days of the retest.
Hearing Loss that Occurs with Aging
You may take into account the hearing loss that occurs as a result of the aging process and retest an employee who has an STS on an audiogram to ensure that the STS is permanent before recording it. When comparing audiogram results, adjust the results for the employee's age when the audiogram was taken using Tables F-1 or F-2, as appropriate, in Appendix F of the Occupational Noise Exposure standard.
Noise Dose
Hearing loss is presumed to be work-related if the employee is exposed to noise in the workplace at an 8-hour time-weighted average of 85 dBA or greater, or to a total noise dose of 50 percent, as defined in OSHA's noise exposure standard.
Noise dose is defined as the amount of actual exposure to noise relative to its permissible exposure limit. A dose greater than 100 percent represents exposure above the limit. For hearing loss cases where the employee is not exposed to this level of noise, refer to the rules in §1904.5 to determine if the hearing loss is work-related.
If a physician determines that the hearing loss is not work-related or has not been significantly aggravated by occupational noise exposure, you are not required to consider the case work-related or to record it on the 300 Log. For example if the hearing loss occurred before the employee was hired; or hearing loss that is unrelated to workplace noise, such as off the job traumatic injury to the ear or infections.
Use this 'decision tree' to determine whether the results of a audiometric exam given on or after January 1, 2003 reveal a recordable STS.
Note: In all cases, use the most current baseline to determine recordability as you would to calculate a STS under the hearing conservation provisions of the noise standard (§1910.95). If an STS occurs in only one ear, you may only revise the baseline audiogram for that ear.* The audiogram may be adjusted for presbycusis (aging) as set out in 1910.95.** A separate hearing loss column on the OSHA 300 Log beginning in Calendar year 2004.
No comments:
Post a Comment