RESPIRATORS: THE MEDICAL EVALUATION
The National Institute for Occupational Safety and Health (NIOSH) says the number of respirator users in America may be as high as 6.5 million workers. Respirators are used when engineering controls aren't feasible, are not yet in place, or don't offer complete protection from hazardous air contaminants. They also offer needed protection in escape and emergency response situations.
But respirators cannot be worn by all workers who may ned or request them, occupational health experts warn. They say that employers must first make sure that employees are medically fit to wear their respirators.
Moreover, OSHA's respirator standard (29 CFR 1910.134), promulgated in 1971, stipulates that as part of an overall respiratory protection program, "Persons should not be assigned to tasks requiring use of respirators unless it has been determined that they are physically able to perform the work and the equipment."
Corky J. Hull, M.D., a consultant with Occupational Health Inc., San Francisco, says some 5 percent of would-be respirator users should not be given medical clearance to wear such equipment. Hull estimates that as many as an additional 15 percent of would-be respirator users should be limited in their respirator use, either by duration (i.e. no more than 2 hours per day), by type (i.e. no self-contained breathing apparatus, which may weigh as much as 35 lb), or by working conditions (i.e. not in atmospheres immediately dangerous to life or health).
Richard Lewis, M.D., a Cleveland-based occupational physician, says, "It's been rare that I've found people who absolutely couldn't wear any type of respirator for physical reasons; that is, their lung capacity was so bad they couldn't handle it." But, to illustrate how an employee's physical condition could rule out respirator use, he offers this worst-case scenario: Having an insulin-dependent diabetic with heart disease wearing a self-contained breathing apparatus (SCBA) in a confined vessel.
Unfortunately, there is no one medical test or set of tests that can unequivocally determine a worker's ability to wear a respirator. Tom Hodous, M.D., an occupational physician with NIOSH, notes that relevant medical considerations can include everything from cardiovascular and pulmonary fitness to claustrophobia. The person's medical condition, Hodous adds, is only one factor, which has to be considered along with such things as the person's age, history of respirator use, type of respirator, duration of use, and work environment.
A good medical evaluation program for current respirator users and prospective hirees considers all these factors and more. It gives employers a consistent, systematic way to identify workers who cannot wear respirators and to track the health status of workers who do wear them.
Frank Grimes, safety and health specialist, United Steelworkers of America, and a longtime respirator wearer, describes respirators as "hot, heavy, and uncomfortable." While that may be a small price to pay in many cases for the protection they afford, the effects of wearing a respirator can go beyond mere discomfort.
The added resistance and dead space associated with some respirators (notably negative-pressure air-purifying types) can make breathing more difficult, notes consultant Sheldon H. Rabinovitz, Ph.D., CIH, of Sandler Occupational Medicine Associates Inc. (SOMA), Melville, N.Y. SCBAs, commonly used in emergency response situations, can weigh as much as 35 lb, he adds, boosting the cardiac stress on a worker. Respirator use has also been associated with diminished senses, higher body temperature, and localized skin irritation.
These effects, Rabinovitz says, pose little risk to the majority of generally healthy workers. However, they can significantly affect workers with existing medical conditions, our respondents warn.
For some workers, Dr. …