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SESSION 6EXPOSURE MONITORING, MEDICAL CONSULTATION, AND EMERGENCIES Upon completion of this session, you will be familiar with hazard assessment and medical services EH&S offers. You will also understand what you need to do in the
event of an emergency. It should take you about 20 minutes to complete this session. When you have read through the material, you will be asked to answer 5 questions. Exposure MonitoringHazard assessments are conducted by EH&S Industrial Hygienis
ts
and other EH&S professionals to identify the potential for employee exposure to hazardous materials and to ensure appropriate control measures are in place. Hazard assessments are conducted for
operations involving the use of particularly hazardous substances,
unstable/reactive compounds, chemicals regulated by OSHA substance specific standards and for other chemicals and operations as deemed appropriate by an EH&S Industrial Hygienist. Operations and materials may
also be assessed in response to a Health Services
referral, or when a concern is expressed by an employee or supervisor.When necessary, monitoring may be conducted as a follow up to a hazard assessment to:
- Identify personnel who are potentially or actually exposed to hazardous chemicals at unsafe levels, including those personnel who report symptoms consistent with exposure;
- Establish the effectiveness of existing controls for new or modified operations/procedures;
- Identify laboratory or shop operations requiring improved controls; and
- Determine the effectiveness of chemical spill/release cleanups.
Three main types of monitoring are conducted by EH&S Industrial Hygienists
. These include:
- Air sampling - Air is sampled and analyzed to determine the presence and concentration of airborne contaminants,
- Wipe sampling - Surfaces (such as bench tops) are tested to determine the presence and amounts of residual contaminants, and
- Bulk sampling - Materials are collected and analyzed to determine the presence and amounts of contaminants such as lead and asbestos. These are normally collected before demolition, construction and
renovation activities.
Interpretation of Monitoring Results Air sampling results are compared to exposure limits to determine if the potential for exposure exists. The
following occupational exposure limits are used:
- The OSHA 8 hour Time Weighted Average Permissible Exposure Limit (PEL) for a substance. Represents an 8 hour time weighted average legal exposure limit that must not be exceeded.
- The American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV). The TLV is a recommended 8-hour, time-weighted average concentration. TLV-TWA
- The OSHA Action Level (AL). An AL, which is normally one-half the substance's PEL, triggers additional monitoring and/or medical surveillance requirements. The AL is measured for a workday i.e., an
8-hour time-weighted average concentration.
- The OSHA and ACGIH Short-Term Exposure Limit (STEL) is the average concentration to which workers can be exposed for a short period of time (15 minutes) without suffering from irritation, chronic or irreversible
tissue damage or narcosis provided that the daily TLV-TWA is not exceeded. The STEL supplements the 8-hour PEL/TLV and is intended to protect workers from acute toxic effects.
- OSHA and ACGIH Ceiling Limits (C). The concentration that should not be exceeded during any part of the working exposure (workday). TLV-Ceiling.
Several individual substances have both OSHA and ACGIH exposure limits. In some cases, the values of these two limits are different. In accordance with Berkeley Lab's Work Smart Standards the
lower of the two limits is used to interpret exposure results. These criteria may vary from substance to substance. The Laboratory uses the lower of the OSHA PELs and ACGIH TLVs for its exposure
criteria. Various criteria exist for evaluating the results from wipe and bulk samples. Employee Notification of Monitoring The industrial
hygienist conducting the exposure monitoring shall give written notification of the monitoring results to the employee (and employee's supervisor) in accordance with the specific OSHA requirements for that
substance. Where no criteria exists, monitoring results will be provided within 15 days of receiving analytical results for the laboratory performing the analyses.. Health Services shall also
be notified of hazard assessments where there is a potentials for exposure and all monitoring results. Medical Consultations Medical consultations are provided by
Health Services to any employee exposed at or above an Action Level (or in the absence of an AL the lower of the PEL and TLV); when an employee develops a sign or symptom of exposure to a hazardous material; or
when an uncontrolled event such as a spill, leak or explosion takes place in which there is a likelihood of a hazardous exposure. Health Services should also be consulted by women who are either pregnant or intend on becoming pregnant.
Medical consultation and examinations are provided under the direction of Health Services, a group within the EH&S Health Department. Berkeley Lab's Health Service Program policies and procedures are described
in PUB 3000, Chapter 3, Health Services.
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