tectors from a variety of suitable hearing protectors provided by the employ er. (4) The employer shall provide training in the use and care of all hearing protectors provided to employees. (5) The employer shall ensure proper initial fitting and supervise the correct use of all hearing protectors. (j) Hearing protector attenuation. (1) The employer shall evaluate hearing protector attenuation for the specific noise environments in which the protector will be used. The employer shall use one of the evaluation methods described in Appendix B: Methods for Estimating the Adequacy of Hearing Protection Attenuation. (2) Hearing protectors must attenuate employee exposure at least to an 8hour time-weighted average of 90 decibels as required by paragraph (b) of this section. (3) For employees who have experienced a standard threshold shift, hearing protectors must attenuate employee exposure to an 8-hour time-weighted average of 85 decibels or below. (4) The adequacy of hearing protector attenuation shall be re-evaluated whenever employee noise exposures increase to the extent that the hearing protectors provided may no longer provide adequate attenuation. The employer shall provide more effective hearing protectors where necessary. (k) Training program. (1) The employer shall institute a training program for all employees who are exposed to noise at or above an 8-hour time-weighted average of 85 decibels, and shall ensure employee participation in such program. (2) The training program shall be repeated annually for each employee included in the hearing conservation program. Information provided in the training program shall be updated to be consistent with changes in protective equipment and work processes. (3) The employer shall ensure that each employee is informed of the following: (i) The effects of noise on hearing; (ii) The purpose of hearing protectors, the advantages, disadvantages, and attenuation of various types, and instructions on selection, fitting, use, and care; and (iii) The purpose of audiometric testing, and an explanation of the test procedures. (1) Access to information and training materials. (1) The employer shall make available to affected employees or their representatives copies of this standard and shall also post a copy in the workplace. (2) The employer shall provide to affected employees any informational materials pertaining to the standard that are supplied to the employer by the Assistant Secretary. (3) The employer shall provide, upon request, all materials related to the employer's training and education program pertaining to this standard to the Assistant Secretary and the Director. (m) Recordkeeping—(1) Exposure measurements. The employer shall maintain an accurate record of all employee exposure measurements required by paragraph (d) of this section. (2) Audiometric tests. (i) The employer shall retain all employee audiometric test records obtained pursuant to paragraph (g) of this section: (ii) This record shall include: (A) Name and job classification of the employee; (B) Date of the audiogram; (C) The examiner's name; (D) Date of the last acoustic or exhaustive calibration of the audiometer; and (E) Employee's most recent noise exposure assessment. (F) The employer shall maintain accurate records of the measurements of the background sound pressure levels in audiometric test rooms. (3) Record retention. The employer shall retain records required in this paragraph (m) for at least the following periods. (i) Noise exposure measurement records shall be retained for two years. (ii) Audiometric test records shall be retained for the duration of the affected employee's employment. (4) Access to records. All records required by this section shall be provided upon request to employees, former employees, representatives designated by the individual employee, and the Assistant Secretary. The provisions of 29 CFR 1910.20 (a)-(e) and (g)-(i) apply to access to records under this section. (5) Transfer of records. If the employer ceases to do business, the employer shall transfer to the successor employer all records required to be maintained by this section, and the successor employer shall retain them for the remainder of the period prescribed in paragraph (m) (3) of this section. (n) Appendices. (1) Appendices A, B, C, D, and E to this section are incorporated as part of this section and the contents of these appendices are mandatory. (2) Appendices F and G to this section are informational and are not intended to create any additional obligations not otherwise imposed or to detract from any existing obligations. (0) Exemptions. Paragraphs (c) through (n) of this section shall not apply to employers engaged in oil and gas well drilling and servicing operations. (p) Startup date. Baseline audiograms required by paragraph (g) of this section shall be completed by March 1, 1984. II. Conversion Between "Dose" and "8-Hour Compliance with paragraphs (c)–(r) of this regulation is determined by the amount of exposure to noise in the workplace. The amount of such exposure is usually measured with an audiodosimeter which gives a readout in terms of "dose." In order to better understand the requirements of the amendment, dosimeter readings can be converted to an "8-hour time-weighted average sound level." (TWA). In order to convert the reading of a dosimeter into TWA, see Table A-1, below. This table applies to dosimeters that are set by the manufacturer to calculate dose or percent exposure according to the relationships in Table G-16a. So, for example, a dose of 91 percent over an eight hour day results in a TWA of 89.3 dB, and, a dose of 50 percent corresponds to a TWA of 85 dB. If the dose as read on the dosimeter is less than or greater than the values found in Table A-1, the TWA may be calculated by using the formula: TWA=16.61 log10 (D/ 100)+90 where TWA-8-hour time-weighted average sound level and D-accumulated dose in percent exposure. 89. 90.. 91.. 92... 93. 95. TABLE A-1-CONVERSION FROM "PERCENT 135 89.2 89.2 89.3 89.4 89.5 89.6 89.6 92.2 140 92.4 145 92.7 92.9 155 93.2 160 93.4 APPENDIX B TO § 1910.95-METHODS FOR ESTIMATING THE ADEQUACY OF HEARING PROTECTOR ATTENUATION This Appendix is Mandatory For employees who have experienced a significant threshold shift, hearing protector attenuation must be sufficient to reduce employee exposure to a TWA of 85 dB. Employers must select one of the following methods by which to estimate the adequacy of hearing protector attenuation. The most convenient method is the Noise Reduction Rating (NRR) developed by the Environmental Protection Agency (EPA). According to EPA regulation, the NRR must be shown on the hearing protector package. The NRR is then related to an individual worker's noise environment in order to assess the adequacy of the attenuation of a given hearing protector. This appendix describes four methods of using the NRR to determine whether a particular hearing protector provides adequate protection within a given exposure environment. Selection among the four procedures is dependent upon the employer's noise measuring instruments. Instead of using the NRR, employers may evaluate the adequacy of hearing protector attenuation by using one of the three methods developed by the National Institute for Occupational Safety and Health (NIOSH), which are described in the "List of Personal Hearing Protectors and Attenuation Data," HEW Publication No. 76-120, 1975, pages 21-37. These methods are known as NIOSH methods #1, #2 and #3. The NRR described below is a simplification of NIOSH method #2. The most complex method is NIOSH method #1, which is probably the most accurate method since it uses the largest amount of spectral information from the individual employee's noise environment. As in the case of the NRR method described below, if one of the NIOSH methods is used, the selected method must be applied to an individual's noise environment to assess the adequacy of the attenuation. Employers should be careful to take a sufficient number of measurements in order to achieve a representative sample for each time segment. NOTE: The employer must remember that calculated attenuation values reflect realistic values only to the extent that the protectors are properly fitted and worn. When using the NRR to assess hearing protector adequacy, one of the following methods must be used: (i) When using a dosimeter that is capable of C-weighted measurements: (A) Obtain the employee's C-weighted dose for the entire workshift, and convert to TWA (see appendix A, II). (B) Subtract the NRR from the C-weighted TWA to obtain the estimated A-weighted TWA under the ear protector. (ii) When using a dosimeter that is not capable of C-weighted measurements, the following method may be used: (A) Convert the A-weighted dose to TWA (see appendix A). (B) Subtract 7 dB from the NRR. (C) Subtract the remainder from the Aweighted TWA to obtain the estimated Aweighted TWA under the ear protector. (iii) When using a sound level meter set to the A-weighting network: (A) Obtain the employee's A-weighted TWA. (B) Subtract 7 dB from the NRR, and subtract the remainder from the A-weighted TWA to obtain the estimated A-weighted TWA under the ear protector. (iv) When using a sound level meter set on the C-weighting network: (A) Obtain a representative sample of the C-weighted sound levels in the employee's environment. (B) Subtract the NRR from the C-weighted average sound level to obtain the estimated A-weighted TWA under the ear protector. (v) When using area monitoring procedures and a sound level meter set to the Aweighing network. (A) Obtain a representative sound level for the area in question. (B) Subtract 7 dB from the NRR and subtract the remainder from the A-weighted sound level for that area. (vi) When using area monitoring procedures and a sound level meter set to the Cweighting network: (A) Obtain a representative sound level for the area in question. (B) Subtract the NRR from the C-weighted sound level for that area. APPENDIX C TO § 1910.95-AUDIOMETRIC MEASURING INSTRUMENTS This Appendix is Mandatory 1. In the event that pulsed-tone audiometers are used, they shall have a tone on-time of at least 200 milliseconds. 2. Self-recording audiometers shall comply with the following requirements: (A) The chart upon which the audiogram is traced shall have lines at positions corresponding to all multiples of 10 dB hearing level within the intensity range spanned by the audiometer. The lines shall be equally spaced and shall be separated by at least 4 inch. Additional increments are optional. The audiogram pen tracings shall not exceed 2 dB in width. (B) It shall be possible to set the stylus manually at the 10-dB increment lines for calibration purposes. (C) The slewing rate for the audiometer attenuator shall not be more than 6 dB/sec except that an initial slewing rate greater than 6 dB/sec is permitted at the beginning of each new test frequency, but only until the second subject response. (D) The audiometer shall remain at each required test frequency for 30 seconds (± 3 seconds). The audiogram shall be clearly marked at each change of frequency and the actual frequency change of the audiometer shall not deviate from the frequency boundaries marked on the audiogram by more than ± 3 seconds. (E) It must be possible at each test frequency to place a horizontal line segment parallel to the time axis on the audiogram, such that the audiometric tracing crosses the line segment at least six times at that test frequency. At each test frequency the threshold shall be the average of the midpoints of the tracing excursions. APPENDIX D TO § 1910.95-AUDIOMETRIC TEST |