Medical surveillance requirements
Your facility is required to conduct medical surveillance for all workers who, for a combined total of 30 or more days per year, are performing asbestos removal work or are exposed at or above the permissible exposure limit.
This includes medical examination and consultation prior to beginning work, at least annually, and upon termination of employment.
The facility must establish and maintain an accurate record for each worker subject to medical surveillance.
These records must be maintained for the duration of the worker’s employment, plus an additional 30 years.
Courtesy of The EPA

What are the permissible exposure limits (PEL) for asbestos?