Establishing the program

For certain designated substances, the control program must provide for: pre-placement, periodic, acute exposure and exit medical examinations and clinical tests as outlined by the Code for Medical Surveillance for Designated Substances (subsection 20(4)). These designated substances are:

  • asbestos
  • benzene
  • coke oven emissions
  • isocyanates
  • lead
  • mercury
  • silica

The Code for Medical Surveillance for Designated Substances should be consulted for more detail.

The employer is responsible for establishing a medical surveillance program and is required to bear the costs of medical examinations and clinical tests as required by the Code for Medical Surveillance for Designated Substances (subsection 20(5)).

Consent to medical surveillance

Although the employer may be required to establish a medical surveillance program, worker participation in the medical surveillance program is strictly voluntary (subsection 28(3) of OHSA).

Requirements for medical examinations

The control program must incorporate provisions for medical examinations that satisfy the requirements of the Code for Medical Surveillance for Designated Substances (the Code) and include:

  • a medical history
  • a physical examination
  • clinical tests required by the examining physician (subsection 20(4))

These examinations are conducted at the following times for workers in jobs involving exposure to designated substance:

  • pre-placement
  • at periodic intervals afterwards
  • where acute exposure occurs (depending on the substance)
  • when a worker leaves their placement

The control program should identify the job classifications for which, due to the nature of exposure to a designated substance, medical surveillance is required. The control program should also include a provision for the selection of the examining physician(s).

Examining physicians

The examining physician may be the company doctor, a private medical consultant contracted for by the employer, a physician on the staff of a clinic whose services are used by the employer, or the worker’s own physician.

In accordance with Code for Medical Surveillance for Designated Substances physicians conducting medical examinations and/or supervising clinical tests of a worker must be competent to do so because of knowledge, training and experience in occupational medicine.

Clinical tests

Clinical tests are an additional indicator of the extent of a worker’s exposure to the substance.  They are particularly useful in cases where knowledge of airborne concentrations of the substance alone may not ensure that a worker is not overexposed (for example, lead). Some clinical tests measure the concentration of the substance in a worker’s blood or urine, thus providing an indication of the amount that has been absorbed. Others are used to measure a specific function of the body that may be affected by exposure.

Some of the medical surveillance program requirements for designated substances in the Code specify “action levels” for the results of clinical tests. When the test results are at these levels, action is called for, as detailed in the Code.  Sometimes two action levels are specified.  When the lower level is reached, the physician is required to review engineering controls, work practices, health status, personal hygiene practices and/or non-occupational sources of the substance.  When the higher level is reached, and this result is confirmed by a second test, the worker must be removed from exposure.

The use of action levels does not mean that clinical tests are intended to be the only indicator used to protect the health of workers. An assessment of a worker’s fitness to continue working in exposure to the designated substance is based on the results of the medical examination in conjunction with the results of any clinical tests. The examining physician must use professional judgement in discerning other signs of possible overexposure to the substance.  The tests provide additional information that could indicate overexposure. T his is particularly important when signs of overexposure or adverse effects are not detected on examination.

Results of medical examinations

Physician’s requirements in advising the employer

The regulation requires a physician who conducts the medical examination or supervises clinical tests to advise the worker and the worker’s employer whether the worker has an occupational illness because of exposure to a designated substance and whether the worker is fit, fit with limitations or unfit to continue working in exposure to the designated substance.  

This determination is a professional judgement based on the results of medical examinations and clinical tests and the requirements of the Code for Medical Surveillance for Designated Substances.

In advising the worker and employer that the worker is fit with limitations or unfit to continue working in exposure to a designated substance, the physician is governed by the Code for Medical Surveillance for Designated Substances and must give this advice without giving or disclosing to the employer the records or results of the examinations or tests.   

It is recommended that each examining physician be given a copy of the assessment under section 19 to help evaluate a worker’s fitness for exposure.

Physician’s requirements in advising others

On advising the worker and the worker’s employer that the worker is fit with limitations or unfit to continue working in exposure to a designated substance, the physician must also advise the JHSC, in writing, along with an opinion as to the interpretation to be placed on the advice. The physician must do so on a confidential basis.

If the physician has advised the worker and the worker’s employer that a worker is fit with limitations or unfit to continue working in exposure to a designated substance,  the physician must promptly  communicate that advice to the Provincial Physician, Ministry of Labour, Training and Skills Development.

Responding to physician’s advice

If the physician advises that a worker is fit with limitations or unfit, the employer is required to act on this information.  The precise action taken will depend on the professional advice of the physician and on the requirements of the regulation and the Code.

If the results of clinical tests are at the action level for removal of the worker from exposure, then further exposure of the worker to the substance must stop. In some circumstances, if test results drop to a permissible level, the worker may return to work.  Where the results of clinical tests have not reached the action level or where there is no specific action level/removal from exposure criteria, the physician may still advise that a worker is fit with limitations or unfit based on other signs of adverse health effects.  In such a case, removal from exposure and return to the usual conditions of work are based on the judgement of the physician.

When a worker must be removed from exposure, this can be accomplished through isolation of the worker from the process or job re-assignment.  Where these are not possible, temporary removal from the workplace may be necessary.

The employer and the committee should look to the advice and information received from the physician to improve workplace control measures.

Records

Physician’s records

In addition to requirements on physicians to keep personal exposure records of workers, a physician who conducts medical examinations or supervises clinical tests of a worker must keep records of the examinations and tests in a secure place. These are to be kept for 40 years from the date the first record was made or for 20 years from the date the last record was made, whichever is longer.  If the physician ceases to be able to keep these records, they must forward them to the Provincial Physician, Ministry of Labour, Training and Skills Development or designate who must keep the records in accordance with the above timelines.

Obtaining copies of records

Copies of a worker’s personal exposure records and the results of medical examinations and clinical tests may be given by the examining physician to the worker or the worker’s personal physician on the request of the worker.  If the worker has died, the records may be released to the next of kin or the worker’s personal representative, upon request.