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Working with Newer Chemicals
The choice of chemistry, be it a single molecule or a blend, is often driven by environmental requirements. Given the plethora of environmental regulatory mandates, employee safety can all too easily be pushed to the back burner.
Toxicologists in Utah recently reported exposure of workers to high levels of n-propyl bromide (nPB, 1-bromopropane). SQRC has reviewed information obtained from OSHA, and we have spoken with some of the researchers involved. According to the OSHA report, the manufacturing process involved spraying an adhesive that contains nPB onto foam as part of the production of foam cushions for furniture. Three employees were seen by emergency room doctors, hospitalized, and diagnosed with bromide toxicity. At least some employees appeared to be exposed to high levels of the adhesive over a period of years.
What changes could be made to make the process safer? The statements
in the OSHA report strongly suggest the need for improved worker safety
worker education. Rather than presenting a negative case-study or rather
than attempting to second-guess what might have been done, the episode
is more productively
used as the inspiration for positive, common-sense, and relatively simple
reminders about the basics of chemical handling. While in this instance
the problem was
exposure to exceedingly high levels of nPB, the bottom line is that any
chemical, particularly any aggressive (or effective) chemical, chemical
blend, or chemical
process, has the potential for worker exposure problems.
Chemical Management Reminders
A written safety and health program is essential, but it is not sufficient. To be of value, the safety program must actually be implemented.
In the course of our own site visits, we occasionally see pro-forma, “canned” hazardous communication programs. There they are, in impressive bound notebooks, taking up space on the shelf. Most of us in the manufacturing world are pre-occupied with production issues, quality issues, cost containment, lean manufacturing, and environmental regulatory concerns. Books of MSDS and lofty tomes of written verbiage are of no value if the appropriate ways of working with both the chemical and the process are not communicated in a compelling and effective manner.
Information about pertinent health/safety policies and procedures need
to be provided to employees in a manner that is clear, definitive, and
All employees have to be educated in managing not just hazardous materials but also the total process. Aside from worker safety, such communication makes sense in terms of product quality. If your management tends to move safety concerns to the back burner, you might remind him or her that safety, process consistency, and product quality can be treated as a single issue. Unsafe practices tend to reflect poorly controlled processes and a high reject rate. When employees are asked to perform a manufacturing process, an employer interested in making a profit teaches employees to achieve a technically correct product. It is imperative that employees are also taught to achieve the appropriate safety, chemical handling, and environmental aspects of the process.
The hazards of the workplace must be clearly and compellingly communicated
to workers. For most of us, information about chemical hazards does not
inherently make for fascinating reading or a compelling lecture. The
challenge is to make
chemical handling information compelling and memorable.
I suspect that we have all seen incorrect chemical handling and poor process management; and this is by no means restricted to supposedly unsophisticated or uneducated workers. Engineers, academics, even rocket scientists have been known to store bottles of toxic, flammable, and reactive chemicals in their offices. Some anonymous colleagues like to store their MSDS book in the refrigerator, presumably to dampen even the mere description of reactivity of incompatible chemicals. This is amusing, unless someone has to find emergency chemical information quickly.
Further, we have the additional challenge of communicating hazards to workers where English comprehension is very limited and where workers are simply not comfortable speaking English. In our inspirational example, the employees using nPB had Hispanic surnames; and it is our unofficial understanding that they were all immigrants. The OSHA report does not indicate the language of the worker safety program. I have long been in favor of having MSDS and safety related programs appropriately translated. Over the years, I have unfortunately heard supervisors say: “Let ‘em learn English, like my grandpa did.” Desirable as this may be for the overall cohesiveness of the Nation, it is vital to communicate important health, safety, and technical information within the comfort level of the workers.
Speaking of comfort level, the most successful safety programs I have seen involve multi-media communication, and with good reason. For one thing, we learn differently. Some of us do better with lectures or demonstrations than with the written text. For another thing, semi-literacy is a reality; I have had to educate workers who were functionally illiterate. Humor helps, a lot. Employees who block out the “red-asphalt” approach to safety training will often remember safety procedures that are presented in a humorous manner.
The bottom line is that employees must understand both the technical aspects of the job and the safety aspects of the job. If you hired them, you have to teach them. If you hired those MIT grads who are convinced the laws of physics don’t apply to them, either re-educate them, or hire different MIT people. If you hired a group of assemblers from a remote South-sea island who speak only an obscure dialect of an unknown language, either learn that language or find a good translator; and get that safety program across to them.
• Just as acceptance criteria and a daily maintenance program for equipment are important, it is imperative to have initial safety training for new employees and to schedule regular safety meetings.
Most successful companies would not purchase production equipment without making sure that it is built to specification, that it performs properly, and that it is maintained properly. This involves initial acceptance criteria, ongoing maintenance, and ongoing performance criteria. In a similar manner, there is a well-established confluence of safety, environmental, and quality issues (Kanegsberg, Kanegsberg, and Unmack). Effective production means more than training workers in performance, worker safety, and environmental issues. Because processes are increasingly complex, training by rote is not enough, we must educate workers both initially and on an on-going basis. Unfortunately, some of the same companies that would never consider running equipment and processes without both acceptance and maintenance criteria consider that “on the job” or “on the spot” safety training is a reasonable approach. Bad idea!
Training is only one aspect; because people are complex (have many variables), you have to actually observe your work force. As is the practice in many companies, the company with the nPB exposure issues had an ongoing drug testing program, both prescreening and random testing. A drug testing program may be useful in some instances; and such a program might be considered quantifiable and easier to manage. As a chemist who at one time designed clinical laboratory tests, including drug tests, it is my opinion that, while such testing may have value in some situations, it cannot replace observation, and communication with employees.
If production equipment began to malfunction in a manner not covered in the Preventive Maintenance program or if the process changed in a manner not covered by normal monitoring, management would very likely take action. In an analogous sense, employees may be sober; they may use no illicit drugs. However, ongoing observation of employee behavior and communication with employees might prompt suspicions concerning overexposure to industrial chemicals. For example, higher than expected lost workdays or a drop in productivity during exposure to a chemical could be a warning sign. It is important to take immediate action if an employee appears to be intoxicated or starts to behave haphazardly, or complains that he or she is “high.” The “high” could very well be attributable to chemicals in the workplace (or perhaps coming from a neighboring workplace); the “high” may not be from a recreational drug.
Perhaps more importantly, we do not want to reach the point of overexposure. Controlling and minimizing exposure to all industrial chemicals is essential to worker safety. In addition, in our experience, reducing chemical loss improves the bottom line and the steps leading to appropriate chemical control tend to go hand in hand with a higher quality product.
In setting up and controlling any industrial process involving chemicals, it is important to evaluate the process on a case by case basis.
I personally cast a jaundiced eye on uncontrolled, highly emissive uses of any chemical; I prefer to see solvent containment that is protective of both employees and the environment. In managing the containment of any solvent for any process, it is important to consider and coordinate the technical, environmental, and safety aspects.
In designing process controls, it is important to consider not just the single employee but any potential negative impact of a control on others in the workplace. For example, where exhaust fans are employed, they have to be placed effectively. Placing fans in a tandem manner can have the undesired effect of pushing vapor-laden exhaust air away from one employee into the breathing zone of other employees.
Then there is the matter of respiratory protection. Engineering controls (where emissions from the process are minimized) are far preferable to employee respiratory protection. However, where respiratory protection is provided, it has to be appropriate to the chemical under consideration. Employees have to understand when it is required, and they have to be trained in how to use it. In some cases, additional personnel monitoring is required. Simply providing the equipment is not adequate. Further, in a number of instances, we have seen workers incorrectly assume that nuisance odor masks will provide protection from chemical vapors.
How do we know what constitutes a high exposure? We don’t always know. Monitor all chemicals and blends, understand what you are using, how your process works, and minimize exposure.
Some people, even some safety professionals, take issue with air sampling when the exposure level has not been firmly set. We do not agree with this attitude, particularly because new chemicals and chemical blends are continuously being introduced. For many if not most chemicals and chemical blends, inhalation studies have not been performed. Other safety professionals and some enforcement people agree with this more prudent approach, citing Section 5 or what is commonly termed the “general duty clause” of the venerable Public Law 91-596. This section alludes to workplaces that are “free from recognized hazards.” I think we have to “recognize” that all industrial chemicals pose potential hazards, depending on how they are used.
As with many halogenated solvents, exposure studies using animals and cell-culture (in vitro) studies are being conducted on nPB. While agencies debate an appropriate exposure limit for nPB, it would seem reasonable to minimize worker exposure, and to document both by analytical techniques, by process design, and by employee education that such exposure has been minimized.
To reiterate, it would seem unreasonable to avoid the concept of Section 5 by adopting process chemicals or chemical blends where the worker exposure profile is not well understood.
Further the prudent employer, when adopting a new mixture to be used repeatedly and in an emissive manner, would do well to analyze the level of all major components of a mixture. There is a plethora of new chemicals on the market, and we know very little about the synergistic or antagonistic behavior of mixtures (This means that, for a mixture of two chemicals, one plus one could add up to greater than or less than two in terms of reactivity, cleaning ability, performance, or health impact.) So even if exposure studies have been conducted for the pure (neat) chemicals, it is very likely that exposure studies have not been done for every blend of those chemicals.
A few concluding thoughts
Let’s recap the major points.
1. A written safety and health program is essential, but it is not sufficient. To be of value, the safety program must actually be implemented.
2. Information about pertinent health/safety policies and procedures need to be provided to employees in a manner that is clear, definitive, and understandable.
3. Just as acceptance criteria and a daily maintenance program for equipment are important, it is imperative to have initial safety training for new employees and to schedule regular safety meetings.
4. In setting up and controlling any industrial process involving chemicals, it is important to evaluate the process on a case by case basis.
5. How do we know what constitutes a high exposure? We don’t always know. Monitor all chemicals and blends, understand what you are using, how your process works, and minimize exposure.
Environmental regulatory requirements and community environmental justice issues are often greater immediate drivers than are employee safety issues, in part because the inspections may be more frequent and fines may be very high.
Workers, assemblers, technicians are the valuable assets of a company. While “zero risk” is impossible, given the availability of engineering controls and of well-contained process equipment, there is no reason to compromise worker safety. If you extract the essence of the five safety reminders, what emerges is:
Understand the process (including the chemicals)
Understand your workforce
Educate your workforce.
These concepts should be familiar to those concerned with enhancing the competitive edge. Indeed, when you implement an employee safety program, you also enhance process control, product quality, and lean manufacturing.
File #305400616, obtained from the Utah Labor Commission, Occupational Safety and Health Division, through a GRAMA request.
Kanegsberg, B., E. Kanegsberg, and J. Unmack, “Safety, Environmental, and Contamination Control,” A2C2 Magazine, March, 2004.
Public Law 91-596, Occupational Safety and Health Act of 1970, section 5, “Duties.”
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