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14300.10 – Recording Criteria for Cases Involving Occupational Hearing Loss
A Standard Threshold Shift (STS) is a change in the average level at which various frequencies of sound can be heard (i.e. a change in the hearing threshold) relative to a baseline audiogram for that employee.
Work-related Hearing Loss means that an event or exposure in the work environment either caused or contributed to the hearing loss, or significantly aggravated a pre-existing hearing loss.
A Baseline Audiogram is the employee’s original audiogram taken at the time the employee was first placed in a hearing conservation program. Baseline audiograms are typically compared to subsequent audiograms to evaluate the effects of employee’s occupational noise exposure over time.
Audiometric Zero represents the statistical average of the levels at which various frequencies of sound can be heard in young adults with no pathology in the ears (i.e. the statistical average hearing threshold). Hearing levels measured at or near Audiometric Zero represent near-perfect hearing.
Under the Cal/OSHA Employer Records of Occupational Injury or Illness Standard (T8CCR 14300.10), a work-related Standard Threshold Shift (STS) is recordable only if the employee has a current audiogram revealing:
Recordable hearing loss cases must be documented on the Cal/OSHA Form 300 (or equivalent) by checking the column for Hearing Loss.
To determine if the hearing loss is work- related use the rules in section T8CCR 14300.5. To evaluate if an employee currently has a STS of 25 dB or greater, first find out if the employee had a recordable hearing loss in the past.
Retesting for a Recordable STS
If a retest:
Retests for a recordable STS must be conducted within 30 days of the test that revealed the recordable STS. If further testing (performed under the requirements of T8CCR 5097) shows that the recordable STS has not persisted, the entry on the Log 300 may be erased or lined-out.
The Cal/OSHA Employer Records of Occupational Injury or Illness Standard (T8CCR 14300.10) defines a work-related, recordable STS as 25 decibels or more (in the same ear averaged at 2000, 3000, and 4000 Hz). By comparison, the Cal/OSHA Noise Standard [(T8CCR 5097 (d) (8)] defines a STS as a change in hearing threshold (compared to the employees baseline audiogram) of an average of 10 decibels or more at 2000, 3000, and 4000 Hz in the same ear. The 10 dB STS is the threshold for further evaluation of the employee’s audiogram as part of T8CCR 5097.