Imagine trying to shield your workers from air-borne chemicals without the benefit of air monitors, permissible exposure limits, ventilation designs, or certified, fit-tested respirators. No way to detect noxious fumes. No values by which to gauge safe levels. No assurance that workersí equipment is actually protecting them. Talk about making your job difficult! Respiratory protection would be near impossible. Yet this is just what youíre up against trying to detect and control hidden hazards that get at workers through their skin.
More than 100 chemicals with OSHA permissible exposure limits for inhalation hazards are also known skin permeants. Like the effects of breathing toxic fumes, when one of these substances is absorbed into the blood stream through the skin, the result can be serious; kidney or liver disease, neurological or reproductive disorders, or cancer.
For instance, about a teaspoonful of styrene (3 milliliters) splashed on a workerís skin can deliver the same dose as the eight-hour inhalation exposure limit-50 parts per million. Just touching a surface contaminated with 1.5 micrograms per square centimeter of the suspected carcinogen acrylamide (a quantity about one-millionth the weight of a paper clip) could equal inhaling one dayís permissible exposure limit, 0.03 milligrams per cubic meter.
But other than a "skin notation" alongside the PEL for permeating chemicals, OSHA offers nothing to help safety and health pros trying to deal with dermal exposures. No limits tell you how much of a chemical can safely contact workersí skin. And even if skin exposure levels were established, no tool like an air monitor exists to measure them.
Likewise, no NIOSH standard, like the one the agency recently updated for respiratory protective equipment, exists to help managers sort through the variety of glove materials available.
NIOSH researcher Mark Boeniger calls the inattention to dermal exposures "one of the greatest failures of OSHA and NIOSH." Other skin experts accuse universities of contributing to the problem by glossing over dermal absorption when training young health and safety professionals.
"If you talk to 100 industrial hygienists, 95 percent of them will know what their plantís airborne exposures are," says dermal absorption expert Tom Klingner. "But ask them whether theyíre protecting workers from dermal exposures and they have no idea." Industrial hygiene graduate students have told Klingner they learned more about dermal exposures during a half-hour conversation with him than they did during their grad school career.
The price of ignorance is that many workers are left with only Mother Natureís thin line of defense. Little more than their skins own stratum corneum (a protective layer no thicker than a strand of hair) comes between them and the toxics they touch. Whatís worse is that some common ways to protect skin such as wearing gloves, applying barrier creams, and scrubbing clean after work doesnít always do the job. In fact, they can raise the risks of dermal absorption.
Thereís no question industry needs help protecting workersí skin. The health effects of dermal absorption are so difficult to trace and can take so long, sometimes a lifetime to detect, that illness data is impossible to collect. OSHA doesnít know how many people are exposed to skin permeating chemicals at work. But the fact that dermal diseases and disorders like dermatitis were long the most often reported job illness in the U.S., only recently displaced by cumulative trauma disorders, indicates that skin protection is overlooked in more than a few workplaces.
Until NIOSH findings, EPA data gathering, or OSHA standards offer any real guidance, youíre on your own. Your task is indeed daunting: dermal dangers can be as obvious as a chemical splash on a torn glove, or as inconspicuous as contaminated safety glasses rubbing the thin skin behind the ears.
Just getting workers to comprehend dermal absorption can be difficult. Inhalation exposures are easy enough to understand. Everyone knows a sneeze can pass a cold through the air. Most people recognize the dangers of breathing cigarette smoke. So itís not a stretch to make the case that chemical contaminated air can be bad for you. But good luck convincing a worker that holding a carbon disulfide contaminated tool in a bare hand day after day can damage his sperm.
Tom Klingner recalls the irony of watching a gardener spray pesticides on flowers outside an industrial hygienistsí convention in Anaheim, Cal., two years ago. "The guy wore hip boots and gloves while he sprayed. When he was done, he went to his truck, pulled off a glove, and then yanked off the other glove and both boots with his bare hands." Providing protective clothing isnít enough, Klingner says. Educating workers and changing their behavior is the other half of the battle.
Trickier still can be the task of tracking the source when employees are dermally exposed. In the poly-urethane industry, where the suspected bladder carcinogen methylene bischloro aniline (MOCA) is a common hazard, the Polyurethane Manufacturers Association has long supported voluntary urine monitoring to detect exposures. Klingnerís firm, Colormetric Laboratories in Des Plaines, Ill., runs urine tests for several polyurethane clients who he says have "set the standard for all industries." Consider a few of his sleuthing stories:
Solutions for these cases were simple: encase paperwork in plastic folders that get removed before passing along from the plant to the office; paint tools used in contaminated areas red as a warning to don gloves; and keep reusable PPE clean and use disposable shoe covers for chemical splashes. The real challenge is educating workers to prevent the exposures in the first place.
These dos and doníts can help minimize risks to the skin: