Considering how often I see it done wrong, I'd say choosing chemical protective clothing is a tough job," says safety consultant Neal Langerman, president of Advanced Chemical Safety in San Diego.
An OSHA regulation (29 CFR 1910.132) states it is the employer's responsibility to determine when personal protective equipment (PPE) is necessary, what type is appropriate and how the equipment is to be used.
When it comes to how to comply with these rules in a specific worksite, however, OSHA is silent. Fortunately, companies have a variety of resources available to help them make these decisions, and another one is in the works.
A committee of the International Organization for Standardization (ISO) is working on a voluntary draft international standard (DIS), ISO/DIS 16602, for chemical protective clothing. If, as now seems likely, the standard is adopted next year, it may be helpful for clothing producers and users.
Neither ISO 16602 nor any other resource, however, can provide easy answers to complex questions that arise at different worksites. For the foreseeable future, the selection, use and maintenance of chemical protective clothing will continue to be a matter of judgment for safety and health professionals.
Experts in the field point to four good sources of information for selecting the appropriate chemical protective clothing:
- OSHA's PPE standard, 29 CFR 1910.132;
- American Society for Testing and Materials (ASTM) standard No. F1296-98, "Standard Guide for Evaluating Chemical Protective Clothing," which can be obtained by calling (610) 832-9585 or via the ASTM Web site, www.astm.org ;
- Trade associations and companies engaged in similar manufacturing activities that often have experience with similar hazards and will usually share safety information; and
- Manufacturers of the protective clothing.
The foundation for selecting chemical protective clothing is hazard analysis, according to Jim Zeigler, Ph.D., a research manager with Dupont Tyvek protective apparel.
OSHA does offer some help here, in a nonmandatory appendix to its PPE standard (29 CFR 1910.132, Appendix B). The appendix begins with a point made by a number of experts that PPE should not be the first line of defense against hazards, but the last. Engineering controls and replacing toxic chemicals with ones that are nontoxic are preferable when possible.
Zack Mansdorf, Ph.D., CIH, CSP, past president of the American Industrial Hygiene Association and vice president of EHS at L'Oreal, identifies three key considerations that must be addressed when using protective clothing to protect workers from chemical hazards:
- Potential toxic effects of exposure,
- Likely routes of entry, and
- Hazards associated with the work assignment.
It is usually unwise simply to choose the most protective clothing, because the greater the degree of protection from chemical hazards, the more likely trade-offs in other aspects of the job will arise.
In an article in the Encyclopedia of Occupational Health and Safety, Mansdorf points to the "inherent conflicts between worker comfort, efficiency and protection."
Thicker barriers offer better protection, but they also decrease ease of movement and user comfort. Especially now that OSHA has issued its final ergonomics rule, this is an issue that cannot be ignored: The use of chemical protective clothing may increase the risk of repetitive motion injuries. In some cases, the use of protective clothing can increase other kinds of risks, such as heat stress and a restricted field of vision.
Higher levels of protection may also result in jobs taking longer, quality suffering and the chance of errors increasing.
To minimize lost productivity and ancillary risks, the entire work situation must always be considered when selecting protective clothing.
"The optimum solution," Mansdorf contends, "is to select the minimum level of protective clothing and equipment that is necessary to do the job safely."
If one is to choose the minimum level of protection, it is obviously essential to obtain reliable data about chemical hazards and the clothing's performance characteristics. Unfortunately, this information is often hard to come by.
Too Much of a Good Thing
As any lover of wine or chocolate can tell you, too much of a good thing is a bad thing. When it comes to chemical protective clothing, Zeigler calls overprotection "the greatest common denominator problem."
Everyone agrees that protective-apparel manufacturers have the responsibility to provide information about performance characteristics of their garments. The problem, according to many safety professionals, is that manufacturers often call for using a higher level of protection than is necessary.
"The manufacturers I work with are very ethical, but in this litigious society, they've got to protect themselves," explained Robert West, emergency response preparedness manager at Texas Instruments.
Zeigler, whose job at Dupont puts him in a position to know about the pressures facing users as well as producers, put it differently.
"The issue is liability, as well as the selling process," he said. "We can't assume responsibility for that clothing decision; we can only share the data." Zeigler indicated that is why it is necessary to have trained safety professionals available to pick the clothing.
West agrees that the responsibility to choose the right level of protection lies with the user. For him, the manufacturer's tests are only a starting point. In addition, he said, user organizations "must have internal processes in place that verify their selection."
When West analyzes an application's specific requirements, he considers factors such as temperature, ventilation and lighting. He might try, for example, to control some of a chemical's vapors by using positive or negative pressure.
"Then, if I do some real-time monitoring to give me more specific data, I don't have to use such a high level of PPE."
Texas Instruments has the resources to perform this kind of job hazard analysis, but West agreed that smaller companies often lack the resources to be so thorough. "That's what's happening out there," he observed.
Some workplaces may use hundreds of chemicals that change often. As Mansdorf noted, there is no currently available PPE barrier that provides protection from all chemicals.
Another problem mentioned by some experts is a lack of uniform standards on exposure limits for chemical hazards. In the absence of such limits, the premise must be to keep exposure to a minimum, but this leads back to problems associated with using clothing that is too protective.
West saw only two options for users: get as educated as possible about what they do, or "rely on the limited information the manufacturers give us, and if it's an overkill, it's an overkill."
Langerman pointed to a more insidious danger, that overprotection may result in employees who resist using the clothing. "It's like when a city puts in too many stop signs; it creates a disrespect for safety," he said.
After sorting through the conundrums of choosing the proper protective clothing, there are further difficulties: maintenance, use and abuse.
Mark McDade is the Paper Allied-Industrial, Chemical and Energy union's health and safety representative at Conoco's Billings, Mont., refinery. He tells a cautionary tale about the need for ensuring that chemical protective clothing is well-maintained.
"We had a substantial leak of HF (hydrofluoric) acid," he said. "And the workers sounded the alarm and went to their safe havens." They needed seven "gas tight" suits to get out. Only two were in good shape.
The others had been sitting on a shelf for years. When the workers opened them up, the suits crumbled in their hands. The rubber had rotted.
"No one was hurt, but it scared us to death," McDade said. Now the refinery checks these suits, which are stored for emergencies, and clothing that is used regularly, every 90 days.
Much of the new clothing that comes in is also tested to make sure it is free of defects.
To save on costs, suits are rotated. The company has learned that this type of clothing has a short shelf life, so it is "use it or lose it." Suits that are reused must be checked regularly to be sure they are not worn out.
The refinery has also changed its procedures with regard to the storage of respiratory protection. "We built special lockers for their respirators, but workers being human beings, they started storing their hot tamales or their sandwiches or whatever in these special lockers," McDade said. In addition, workers would not clean up the PPE properly.
Every time workers go to get full-face or half-face respirator masks, they get a new one so there is no chance it is clogged or dirty.
McDade explained that the refinery no longer uses several brands of self-contained breathing apparatus. "The masks, hoses and the rest of it weren't interchangeable," he said. "So we picked one kind, and this has given us a great deal of security."
McDade stressed the importance of understanding chemical risks and how protective measures work. He said everyone at the refinery -- workers and managers -- receives 16 hours of "refresher" training each year on the use of PPE.
More Information Coming
Jeff Stull, principal of International Personnel Protection in Austin, Texas, and the ISO are working on a draft international standard, ISO 16602, that he believes will help users decide what kind of protective clothing is appropriate.
The ISO standard classifies protective clothing in terms of its material and its overall performance. Some materials do better against some hazards than others, so this information is important.
"But even if a garment has great materials, if it's not properly made, it isn't protective," Stull warned.
The movement of a chemical through a protective clothing barrier is called permeation. Stull said permeation rates for a variety of chemicals will be provided for different garments. In addition, there will be ratings for other properties, such as abrasion resistance.
Asked if ISO 16602 will be helpful to users, Zeigler replied, "The jury's still out on that."
The ISO standard comes from an international group of producers, and Zeigler believes the greatest common denominator problem could be driving the classifications to a fairly high level of protection. "Users out there are not crying for this standard," he concluded.
Langerman has a mixed reaction to the ISO 16602 draft. He said the inclusion of information on resistance to flame is "incredibly useful." He also liked the definitions of protective suits but found them complicated.
Langerman pointed to a number of important issues the standard does not address: gloves, boots, eye and face protection, biological ionizing radiation, radioactive contamination, thermal hazards or PPE for chemical emergencies.
As for the decision logic, Langerman found it complicated and difficult to use, in part because it relies on new definitions of the protective clothing spelled out in the standard.
Stull is the first to concede that even the complex decision logic in ISO 16602 will not deal with all trade-offs confronting users of chemical protective clothing.
"There are too many potential situations where it's impossible to predict what should be done," he said. "Judgments still have to be made."