Center for Asbestos Safety

Asbestos Standards

Work Classifications

The OSHA standard uses a classification system that determines which procedures must be followed depending on how the employee is exposed:

Class I: Removal of asbestos materials in insulations systems and sprayed or trowled-on surfaces. Employers must assume any thermal system insulation and surfacing material in construction built before 1981 is in this class.

Class II: Removal of materials that don't fall under Class I, including flooring and roofing material.

Class III: Repair and maintenance in areas where asbestos is present.

Class IV: Custodial duties around surfaces exposed to asbestos.


Workers cannot be exposed to more than an 8-hour time-weighted average of 0.1f/cc, nor a concentration of asbestos above 1 f/cc as averaged over a sampling period of 30 minutes.

All workers who will be exposed to levels exceeding this standard or perform Class I-IV work must undergo training before assignment, with annual follow-ups.

Employers must monitor airborne fibers to assess employee exposure and designate a "competent person" to identify and correct unsafe exposure levels. This person must be qualified through state or EPA-approved programs. In Class III and IV situations this person must compete an asbestos-specific 16-hour EPA operations and maintenance course.

Before work begins, the competent person must perform an initial exposure assessment. If exposure levels are found to be above the permissible exposure limit (PEL), this person must provide information to ensure that control systems are put in place and maintained. This is judged by the results of employee exposure monitoring and observations, information, or calculations indicating employee asbestos exposure.

For Class I asbestos work, unless documented that employees will not be exposed greater than 8-hour TWA PEL and short-term exposure limit STEL, it must be assumed exposure will be above those limits.

A negative exposure assessment shows that employee exposure will be below the PEL. This must be demonstrated with data showing airborne fibers will not exceed the 8-hour TWA PEL or STEL, either with exposure data from work done in the past twelve months, or by current exposure monitoring on each employee for the entire job.

Employers must take at least one breathing zone sample representing full-shift exposure, and thirty minute exposures for operations most likely to put employees above the limit. Affected employees and their representatives must have access to exposure monitoring.

Class I and II work must be monitored daily unless there has been a negative exposure limit throughout the job, or if all employees use positive-pressure respirators. Other classes only require monitoring when exposure can exceed PEL.


Education requirements for employees:

Class I: EPA Model Accreditation Plan (MAP) asbestos abatement worker training.

Class II: Class I training, plus an eight-hour course that includes hands-on experience.

Class III: Sixteen hours of training including hands-on experience.

Class IV: EPA awareness training as required for competent persons, plus two hours of training including the locations of ACM (asbestos containing material) and PACM (presumed asbestos containing material), as well as detection of warning signs of asbestos exposure.

Reporting Asbestos Hazards

Before work begins, building owners must identify all thermal system insulation, sprayed or troweled-on surfacing materials, and resilient flooring material installed before 1981. Any ACM or PACM found must be reported to employers bidding for work in or near these areas and employees working in or near the building . Tenants must be notified of any ACM.

Employers who find ACM on a worksite must notify the building owner and other on-site employers within 24 hours. Employers and owners in nearby areas must be instructed on how to reduce airborne asbestos. Within ten days of project completion, the building owner and employers must be notified of final monitoring results and any remaining ACM.

Medical Surveillance

Medical exams and consultation must be provided for Class I-III employees after thirty days of exposure exceeding PEL or STEL, before any job using negative pressure respirators, and when advised by a physician. If an employee has passed an exam in the past twelve months another exam isn't required.

Medical exams must include a standardized questionnaire on the initial exam and an abbreviated questionnaire with annual exams, a physical exam of pulmonary and gastrointestinal health, and anything else the physician deems necessary.

Employers must provide the examining physician a copy of OSHA's asbestos standard, a description of the employee's duties involving exposure, the employee's represented or anticipated exposure level, a description of protective equipment used, and any other information from previous exams.

The employer must obtain the physician's opinion on the exam results in writing, as well as information on any medical conditions that may make the employee more susceptible to asbestos, recommended limitations on the employee or safety equipment, and statements that the employee has been informed of the exam's results, and that lung cancer risk increases when combining smoking and asbestos exposure.

Records must be kept of the exams, asbestos testing data, asbestos measuring procedures, and safety equipment used. These records must be available when requested by affected employees, former employees, their designated representatives, or OSHA's Assistant Secretary.

Warning Labels

Sings must be posted at the entrance of areas with ACM or PACM, identifying the material present, their location, and appropriate work practices around them. Warning signs must be posted to instruct employees on the dangers and necessary steps they must take before entering the area.

All products and waste containers with more than 1% asbestos content must have a hazard label with the following text:


Center for Asbestos
Safety in the Workplace