ARA for Technical Support
Directorate of Technical Operations
Directorate of Technical Support
Office of Occupational Medicine
Interpretation of 1910.1043(h)(ii)(c)
1. Medical surveillance as required in paragraph (h)(3)(i) of the
standard, shall be provided every 6 months for all employees with FEV1 values
of less than 80 percent of the predicted value (h)(ii)(c). However, if the
FEV1 is greater than 80 percent BUT there is a FEV1 decrement of 5 percent
(or greater) that is 200 ml (or more) on the first working day (that is the
difference between the first test conducted on entering the workplace after
an absence of at least 35 hours, and the second test conducted between 4 and
10 hours after beginning the work shift), that will require a re-test in 6
In addition to the above, (h)(ii)(c) mandates that if the physician
finds a significant change in the responses to the questionnaire which the
worker completes as part of the medical history, or in any aspect of the
pulmonary function test (PFT) results or other diagnostic tests he/she will
provide another PFT in 6 months.
Because "significant change" depends on findings which are too
numerous and varied to list and on the physician's interpretation of those
findings based on his/her experience and training, the "significant change"
is not defined. The standard relies on the physician's opinion.
2. FEV1/FVC ratios are referred to in Appendix D of the standard as part
of NIOSH guidelines. A drop below 0.75 of the FEV1/FVC ratio is suggested as
an indicator for a repeat evaluation within 1 month. However, it must be
noted these are recommendations, not mandated requirements. The FEV1/FVC
ratios do change with age but the test is a relatively reliable indicator of
obstructive lung disease.