3.3 OSHA Exposure Limits, Exposure Assessments & Medical Surveillance (29 CFR 1926.1101)

3.3 OSHA Exposure Limits, Exposure Assessments & Medical Surveillance

Quick Answer: Under 29 CFR 1926.1101(c), no employee may be exposed above 0.1 fiber per cubic centimeter (f/cc) as an 8-hour time-weighted average (TWA) or above 1.0 f/cc averaged over 30 minutes (the excursion limit). A competent person must assess exposure at the start of each operation. Class I and II jobs need daily personal monitoring unless a valid negative exposure assessment (NEA) exists. Medical surveillance is required for workers who, for a combined total of 30 or more days per year, do Class I, II, or III work or are exposed at or above a PEL. Days of Class II or III work on intact material lasting one hour or less with full work-practice compliance are not counted.

The Two Permissible Exposure Limits

• Both limits are measured by phase contrast microscopy fiber counts: fibers 5 micrometers or longer with a length-to-diameter ratio of at least 3:1, per OSHA's reference method in Appendix A to 1926.1101.
• OSHA lowered the PEL from 0.2 to 0.1 f/cc in 1994. The construction standard has no separate action level. The PEL and EL themselves trigger controls, respirators, regulated areas, and medical surveillance.
• A PEL is a legal ceiling, not a safe level. Exposure should be kept as low as feasible.

Exposure Assessments (29 CFR 1926.1101(f))

Initial Exposure Assessment

A competent person must perform an exposure assessment immediately before or at the start of each asbestos operation. The purpose is to decide whether exposure may exceed a PEL. For Class I work, until the employer shows exposures are below the PELs, the employer must presume employees are exposed above the TWA and EL.

Negative Exposure Assessment (NEA)

An NEA demonstrates that employee exposure during an operation will be below both the TWA and the EL. It can be based on one of three types of data:

1. Objective data showing the product or activity cannot release fibers at or above the PELs under expected conditions.
2. Prior monitoring data from the past 12 months for closely similar operations, with the same process, material, controls, work practices, and conditions, performed by employees with equal or less training and experience.
3. Initial monitoring on the current job showing results below the PELs.

Daily and Periodic Monitoring

• Class I and II work: daily monitoring representative of each employee in the regulated area, unless the employer has an NEA for the entire operation.
• Even with an NEA, monitoring must be repeated when conditions change. Examples include a new process, a new type of material, or a different control method, or when the competent person believes exposures may exceed a limit.
• Employees must be notified of results as soon as possible, and no later than 5 working days after the employer receives them, either individually in writing or by posting in an accessible location (1926.1101(f)(5)).
• Samples are collected in the breathing zone. OSHA's Appendix A method places the open-face cassette on the collar or lapel about 10 cm from the nose and mouth.

Medical Surveillance (29 CFR 1926.1101(m))

Who Is Covered

The employer must provide a medical surveillance program for every employee who, for a combined total of 30 or more days per year:

• Is engaged in Class I, II, or III asbestos work, or
• Is exposed at or above a PEL.

Day-counting exception: A day of Class II or Class III work on intact material lasting one hour or less, counting the whole removal operation including clean-up, is not counted if the worker fully follows the standard's work practices.

Separately, any employee required to wear a negative-pressure respirator must be physically able to do the work and use the equipment, as determined under a physician's supervision.

When Exams Are Given

What the Exam Includes

• A medical and work history emphasizing the pulmonary, cardiovascular, and gastrointestinal systems.
• OSHA's standardized questionnaire (Appendix D): the full version at the initial exam and the abbreviated version annually.
• A physical exam directed to the pulmonary and gastrointestinal systems.
• A chest X-ray (14 x 17 inch or other reasonably sized film or digital posterior-anterior view) at the physician's discretion, classified under Appendix E, which uses the ILO system and qualified readers such as B Readers.
• Pulmonary function tests measuring FVC and FEV1. Non-physicians who administer spirometry must complete an academic or professional spirometry training course.
• Any other test the physician considers necessary.

All exams are performed by or under a licensed physician, at no cost to the employee, and at a reasonable time and place.

Information the Employer Gives the Physician

1. A copy of the standard and Appendices D, E, and I.
2. A description of the employee's duties related to exposure.
3. The employee's representative or anticipated exposure level.
4. The PPE and respirators used or to be used.
5. Information from previous exams not otherwise available.

The Physician's Written Opinion (1926.1101(m)(4))

The employer must obtain a written opinion that includes:

• Whether the employee has any detected condition placing them at increased risk of material health impairment from asbestos.
• Any recommended limitations on the employee or on the use of PPE such as respirators.
• A statement that the employee was informed of the results and of any conditions that may result from asbestos exposure.
• A statement that the employee was informed of the increased lung cancer risk from the combined effect of smoking and asbestos.

The employer must instruct the physician not to reveal specific findings or diagnoses unrelated to occupational asbestos exposure. The employer gives the employee a copy within 30 days of receiving it.

Workers Who Cannot Wear a Respirator

If the physician finds an employee unable to function normally while using a required respirator, the employee must be assigned to another job or offered a transfer. Any transfer must be with the same employer, in the same area, and with the same seniority, status, rate of pay, and benefits (1926.1101(h)(2)(ii)). An employee may also choose a PAPR instead of a negative-pressure respirator if it gives adequate protection.

Recordkeeping (29 CFR 1926.1101(n))

Employees and their designated representatives have access to their exposure and medical records under 29 CFR 1910.1020. When an employer ceases business, records go to the successor employer or as 1910.1020 directs.

Exam Traps

• The 30-day count has an exception. Short Class II or III jobs on intact material, lasting one hour or less with full work-practice compliance, do not count. Other days count regardless of how short the work was.
• "Within 10 working days" after the 30th day, not "within 30 days."
• The chest X-ray is at the physician's discretion. Pulmonary function tests (FVC and FEV1) are required content.
• No termination exam is listed in the construction standard's frequency rules. That requirement comes from the general industry standard, 1910.1001.
• The written opinion excludes unrelated diagnoses. The employer learns fitness and limitations, not private medical details.

Worked Scenario

A crew removes intact vinyl floor tile (Class II) using wet methods and all required work practices. Each day's job, including clean-up, takes 45 minutes, on 32 days in a year. Because each day is Class II work on intact material lasting one hour or less with full compliance, those days are not counted toward the 30-day trigger for medical surveillance. If the same crew spent two hours a day, or if the tile were broken and friable, each day would count, and surveillance would be required after the 30th day, with an exam due within 10 working days. Separately, any worker assigned to wear a negative-pressure respirator must be medically cleared before that assignment.