Chapter 4


Approved by Tim Roberts
Revised 12/13

4.1 Policy
4.2 Scope
4.3 Applicability
4.4 Exceptions
4.5 Roles and Responsibilities
4.6 Definitions
4.7 Required Work Processes

Work Process A. General Requirements
Work Process B. Requesting an Exposure Assessment
Work Process C. Controlling Exposures

4.8 Source Requirements
4.9 Reference Documents
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4.1 Policy

Berkeley Lab's Exposure Assessment policy requires that Laboratory personnel exposure to chemical and physical workplace hazards not exceed established occupational exposure limits. The Exposure Assessment policy further requires that exposures be minimized through hazard elimination, engineering controls, personal protective equipment (PPE), and administrative controls.
Occupational exposures addressed by this policy include, but are not limited to, chemicals and physical agents (e.g., noise, hot and cold extremes, non-ionizing radiation). Note: Assessments for confined spaces, lasers, ergonomics, biological agents, and radiological exposures are handled by their respective programs.

4.2 Scope

Berkeley Lab is committed to maintaining a safe and healthful workplace. Part of that commitment involves limiting exposures to materials or agents that could be associated with health hazards. The Industrial Hygiene Group oversees non-radiological exposures, and the Radiation Protection Group manages exposures to radiation-related hazards. The process involves measuring or otherwise determining worker and workplace exposure and comparing the exposure with established safe levels.

In addition to chemicals such as beryllium, asbestos, and lead, which have their own Berkeley Lab programs, overexposure to many other substances could be harmful. Regulatory limits are established by Department of Energy (DOE) 10 CFR 851, Worker Safety and Health Program, which includes the Permissible Exposure Limits established by the Occupational Safety and Health Administration (OSHA) as well as the Threshold Limit Values set forth by the American Conference of Governmental Industrial Hygienists (ACGIH).

In addition, physical agents such as noise, non-ionizing radiation (e.g., radio-frequency or microwave radiation), and thermal (heat or cold) stress can induce injury if a worker is overexposed.

4.3 Applicability

This policy applies to Berkeley Lab managers, supervisors, employees, and affiliates who might be exposed to chemical or physical hazards at Berkeley Lab or during Laboratory-sponsored work.

4.4 Exceptions


4.5 Roles and Responsibilities



Potentially Exposed Workers

  • Request an Exposure Assessment if there is concern about potential exposure, and follow all guidance provided in training and Work Processes to evaluate and control exposures

Supervisors and Work Leads

  • Request an Exposure Assessment if there is concern about potential exposure
  • Ensure that persons within their areas of responsibility comply with this policy and its implementing documents, and have completed the required training prior to beginning work

Industrial Hygiene Subject Matter Expert

  • Is responsible for development, approval, revision, and administration of this policy and its implementing documents

Industrial Hygienist

  • Facilitates appropriate Exposure Assessment

Line Managers

  • Ensure that persons within their areas of responsibility comply with this policy and its implementing documents, and notify the Industrial Hygiene Group of process changes that may affect employee exposures

4.6 Definitions




For purposes of workplace evaluations and setting priorities, a job (or portion of a job) involving a discrete agent or set of agents to which workers may be exposed. The word "task" is sometimes used in a similar manner.

Baseline Exposure Assessment

A Baseline Exposure Assessment is a process to screen activities to help determine associated risks and hazards. These assessments are generally qualitative, although some quantitative data (collection or review) may be involved.

Chemical Agents

Include all chemicals used at the Laboratory (or in Laboratory-sponsored work). This includes pure chemicals; mixtures (such as paint or cleaning agents); and materials such as asbestos, silica, and engineered nanomaterials.

Engineered Nanomaterials

Discrete materials having structures with at least one dimension between 1 and 100 nanometers, and intentionally created, as opposed to those that are naturally or incidentally formed. Engineered nanomaterials do not include larger materials that may have nanoscale features (e.g., etched silicon wafers), biomolecules (e.g., proteins, nucleic acids, and carbohydrates), or materials with Occupational Exposure Limits (OELs) that address nano-size particles for that substance.


Inhalation, ingestion, absorption, injection, or contact with a chemical, biological, or physical agent

Exposure Assessment

The process of defining exposure profiles and judging the acceptability of workplace exposures to environmental agents. These assessments may be quantitative, semiquantitative, or qualitative. These assessments are generally conducted by an Environment, Health & Safety (EHS) professional, which may include industrial hygienists or safety engineers. These assessments may be conducted for representative employees and are not required for each individual. In all cases, employees have full access to exposure-monitoring information, including situations where an individual's exposure is not monitored.

Hazard Assessment

A preliminary evaluation (or screening) of an activity to determine if a more comprehensive Exposure Assessment is required. Hazard Assessments can be performed by work leads, supervisors, workers, or an EHS professional. Hazard Assessments are one form of Baseline Exposure Assessment.

Industrial Hygiene

The art and science of anticipation, recognition, evaluation, and control of occupational health hazards (including exposures to chemicals, noise, and non-ionizing radiation)

Occupational Exposure Limit (OEL)

The maximum concentration of an air contaminant to which working people can be exposed for a specified time interval, usually the maximum average exposure allowed throughout an entire eight-hour shift. OELs are typically Permissible Exposure Limits (PELs) or Threshold Limit Values (TLVs), which are defined in this section. In the absence of formally recognized or regulatory-defined OELs, a chemical manufacturer may establish an appropriate exposure limit. Alternatively, the occupational health staff will determine or develop an appropriate protective level. This process often involves industrial hygiene, occupational medicine, and toxicology staff members. The National Institute for Occupational Safety and Health also publishes Recommended Exposure Limits (RELs), which may be evaluated for use.

Permissible Exposure Limit (PEL)

The OSHA Permissible Exposure Limits are exposure levels considered safe for employee exposure in the workplace. Permissible exposure limits for airborne concentrations of hazardous materials are listed in 29 CFR 1910, Subpart Z, and 29 CFR 1926, Subpart Z; and for physical agents (e.g., noise and non-ionizing radiation) in 29 CFR 1910, Subpart G.

Physical Agents

Agents such as noise, hot and cold extremes, and non-ionizing radiation (e.g., radio-frequency, electromagnetic, microwave, and magnetic fields). Laser exposure is addressed by the Laser Safety Program (See the ES&H Manual Laser Safety program).

Professional Judgment

The application and appropriate use of knowledge gained from formal education, experience, observation, experimentation, inference, peer review, and analogy. It allows an experienced industrial hygienist with incomplete or a minimum amount of data to estimate worker exposure in nearly any scenario (adapted from DOE Guide G 440.1 and AIHA’s A Strategy for Assessing and Managing Occupational Exposures, third edition), although such judgments and their basis should be documented.

Qualitative Exposure Assessment

The estimation of exposure determinants based on integration of available information and professional judgment (adapted from DOE Guide G 440.1-3, Occupational Exposure Assessment)

Quantitative Exposure Assessment

The determination of exposure based on collection and quantitative analysis of data sufficient to adequately characterize exposures (adapted from DOE Guide G 440.1-3, Occupational Exposure Assessment,  and AIHA’s A Strategy for Assessing and Managing Occupational Exposures, third edition)

Threshold Limit Values (TLVs)

Airborne concentrations of materials to which nearly all workers may be repeatedly exposed without adverse effect. These values are developed and published by the American Conference of Governmental Industrial Hygienists (ACGIH). Different values are established for eight-hour time-weighted averages, ceilings, and Short-Term Exposure Limits (STELs). Other TLVs are available for nonchemical exposures, such as noise and non-ionizing radiation.

4.7 Required Work Processes

Work Process A. General Requirements

Every Berkeley Lab worker has a right to a safe workplace. In addition to physical hazards, this includes protection from overexposure to chemicals. Laboratory requirements for safe exposure to chemicals are set forth in 10 CFR 851, DOE’s Worker Safety and Health Program rule. This regulation establishes safe work practices, necessary training, and allowable limits to help assure worker protection. One part of the requirements (10 CFR 851.21) specifies the need to identify and assess workplace hazards, including the potential for employee exposure. These assessments can be conducted using multiple methods, including representative air monitoring, estimation, or other modeling.

Based on standard practices, some routine activities, such as use of small quantities of low-hazard chemicals in enclosed systems, may not require additional evaluation. Making these determinations is referred to as Hazard Assessment and is initiated and completed as part of the Job Hazards Analysis (JHA). A more rigorous process is Exposure Assessment, which involves a systematic evaluation of a work activity. These assessments are normally conducted by Berkeley Lab industrial hygienists from the EHS Division and may be initiated from the Work Planning and Control Process (such as JHAs), employee requests, walkthroughs, or other means. Some activities have been characterized and may not need further evaluation.

Berkeley Lab’s Industrial Hygiene Group is updating the Exposure Assessment Program and the JHA to assure that potential exposures are evaluated and that workers are properly protected. For more information on Exposure Assessment, contact your division safety coordinator or EHS Liaison, or refer to the Berkeley Lab Exposure Assessment Program Web site.
Exposure Assessments may be Qualitative or Quantitative:

The Exposure Assessment Program should be evaluated for effectiveness. This is routinely done through the Laboratory's ESH Technical Assurance Program.

Work Process B. Requesting an Exposure Assessment

Berkeley Lab workers have a right to records that may be related to their exposure or medical status. This includes Hazard and Exposure Assessments, results of medical surveillance, and other exposure-related information, such as Material Safety Data Sheets.

Work Process C. Controlling Exposures

Prior to handling chemicals or other materials that might produce harmful exposures, or in areas where there are loud noises or temperature extremes, workers must complete training that covers (a) hazards and (b) methods for controlling the hazards. Examples of such training courses include: EHS0345, Chemical Hygiene for Facilities; EHS0348, Chemical Hygiene and Safety; EHS0356, Nano Safety for Crafts and Technical Work; EHS0310, Respirator Training; and EHS0330, Lead Worker Training. Users of hazardous chemicals/materials must follow training guidance and written procedures covering:

  1. Exposure controls
  2. Use of controls for chemical handling, including PPE

Controls should be protective at least to the level of Permissible Exposure Limits (PELs) and Threshold Limit Values (TLVs).  Controls may include one or a combination of the following:

  1. Hazard Elimination, such as:
    1. Eliminating the agent
    2. Substituting the agent for one of less or no hazard
  2. Engineering Controls, such as:
    1. Shielding
    2. Ventilation
  3. Administrative Controls, such as warning signs and postings
  4. PPE, such as:
    1. Respiratory protection
    2. Protective gloves

4.8 Source Requirements

4.9 Reference Documents

Document Number



Lead Hazards and Controls






Heat Stress


Non-Ionizing Radiation


Other References



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