Section 850.24 - Exposure monitoring(a)General. The responsible employer must ensure that: (1) Exposure monitoring is managed by a qualified individual (e.g., a certified industrial hygienist); and(2) The individuals assigned to this task have sufficient industrial hygiene knowledge and experience to perform such activities properly.(b)Initial monitoring. The responsible employer must perform initial monitoring in areas that may have airborne beryllium, as shown by the baseline inventory and hazard assessment. The responsible employer must apply statistically-based monitoring strategies to obtain a sufficient number of sample results to adequately characterize exposures, before reducing or terminating monitoring.(1) The responsible employer must determine workers' 8-hour TWA exposure levels by conducting personal breathing zone sampling.(2) Exposure monitoring results obtained within the 12 months preceding the effective date of this part may be used to satisfy this requirement if the measurements were made as provided in paragraph (b)(1) of this section.(c)Periodic exposure monitoring. The responsible employer must conduct periodic monitoring of workers who work in areas where airborne concentrations of beryllium are at or above the action level. The monitoring must be conducted in a manner and at a frequency necessary to represent workers' exposure, as specified in the CBDPP. This periodic exposure monitoring must be performed at least every 3 months (quarterly).(d)Additional exposure monitoring. The responsible employer must perform additional monitoring if operations, maintenance or procedures change, or when the responsible employer has any reason to suspect such a change has occurred.(e)Accuracy of monitoring. The responsible employer must use a method of monitoring and analysis that has an accuracy of not less than plus or minus 25 percent, with a confidence level of 95 percent, for airborne concentrations of beryllium at the action level.(f)Analysis. The responsible employer must have all samples collected to satisfy the monitoring requirements of this part analyzed in a laboratory accredited for metals by the American Industrial Hygiene Association (AIHA) or a laboratory that demonstrates quality assurance for metals analysis that is equivalent to AIHA accreditation.(g)Notification of monitoring results.(1) The responsible employer must, within 10 working days after receipt of any monitoring results, notify the affected workers of monitoring results in writing. This notification of monitoring results must be:(i) Made personally to the affected worker; or(ii) Posted in location(s) that is readily accessible to the affected worker, but in a manner that does not identify the individual to other workers.(2) If the monitoring results indicate that a worker's exposure is at or above the action level, the responsible employer must include in the notice:(i) A statement that the action level has been met or exceeded; and(ii) A description of the corrective action being taken by the responsible employer to reduce the worker's exposure to below the action level, if practicable.(3) If the monitoring results indicate that worker exposure is at or above the action level, the responsible employer must also notify DOE and the SOMD of these results within 10 working days after receipt.