The personal and environmental monitoring equipment on the market today makes the instruments used 10 or 15 years ago seem positively Paleolithic.
Back in the stone age of industrial hygiene monitoring, individuals learning how to sample for air pollutants in the workplace had to assemble their own filters after weighing the filter media. In addition, they had to buy the pumps, calibrate them and try to find an analytical method that would allow them to get meaningful and reproducible results.
Many of the instruments now available can calibrate themselves, calculate time-weighted averages and short-term exposure limits and operate with the touch of a couple of buttons. Personal air monitors are easy-to-use and require very minimal training, which means that even the least-experienced person can obtain exposure readings.
But the best IH sampling equipment in the world is useless if workers are not educated in how to use it … and sometimes even education doesn't go smoothly, says Beverly Cohen, an industrial hygienist for 25 years and chair of the board of directors of the American Conference for Governmental Industrial Hygienists.
While visiting China, she showed a group of technicians how to use passive badge dosimeters, which are small plastic enclosures that have sorbent material that trap organic gases and vapors. She trained them how to take the dosimeters out of the packaging and to place them on workers. She showed them how to take the membrane off to collect it for analysis — even taking the dosimeters apart to show them how the instruments worked.
“When I got to the workplace, the workers were wearing the monitors,” Cohen remembers. But unfortunately, they had removed the membrane and exposed the charcoal filter material. “They misunderstood,” she adds. The exposure times and circumstances were not controlled. No exposure times were written down. Nothing was taken to the lab for analysis. “People have to know what they are doing and they have to be trained,” she says.
Cohen, who also chairs the ACGIH Air Sampling Instruments Committe, says that there is more to a successful industrial hygiene monitoring program than pushing a couple of buttons. Just because a piece of equipment has become eaiser to use, it doesn't mean that the worker should be left on his or her own to use it.
Cohen doesn't deny that today's high-tech equipment has contributed to worker safety and health because it can be more affordable than in the past and easier to use. However, Cohen points out that now more than ever, it's important to ensure that the IH program is being supervised by an experienced industrial hygienist or safety professional who can make sure the air sampling is being done correctly and who can accurately interpret the measurement results.
Technicians Must Be Well Trained
A well-trained industrial hygiene or safety professional will know the subtleties, variables or complications that come into play when carrying out an industrial hygiene monitoring program. Therefore, regardless of how technologically advanced a piece of equipment may be, it is important for companies to have someone on staff who is educated in all aspects of conducting personal and environmental monitoring and sampling, Cohen says.
“The person taking the sample has to be very well-trained. Taking a sample can be costly, because you are paying to have the sample analyzed and you're paying to collect the sample,” says Cohen. “It's really important to keep in mind that the smallest mistake can make your measurement invalid.”
Inexperienced personnel are more prone to making “silly mistakes,” according to Cohen. For instance, she says she has seen cases where workers confuse the tissue paper packing material surrounding the filters with the filters themselves. She also has seen cases where the filters weren't tightened so that the air went around the filter, which contributes to inaccurate measurements. These mistakes are small in nature, Cohen notes, but are highly consequential in the long run as the sampling can produce an incorrect reading.
“You want to use the results to find out if things are well under control or whether you have to take some sort of action,” says Cohen. “An incorrect number can jeopardize that.”
However, this doesn't mean that the person doing the monitoring has to be an industrial hygienist, according to Cohen. If an industrial hygiene program is well-lanned and executed by a safety professional or industrial hygienist, a non-IH technician who is well-trained can conduct the monitoring, Cohen says.
Asking the Right Questions
Adequate training is important, Cohen asserts, because conducting an effective monitoring program means more than taking measurements. The worker conducting the monitoring or analyzing the results needs to understand the context of the measurement.
“What you need is someone who is trained in knowing how to control the hazards of a workplace,” she says.
Planning such a program is a huge undertaking and is best left to industrial hygienists who understand the process and the plant's operations. By utilizing their skill set and the results of monitoring, they can control the work environment reduce exposure to hazards.
Part of the program is assessing the areas where there is potential for worker exposure. Some of the questions safety professionals should be able to answer when starting a monitoring program, says Cohen, are why sampling is needed and what are the potential exposures for employees, the environment or the surrounding community.
Some companies, such as IBM, have ongoing statistical sampling programs, where workers regularly are monitored in case an epidemiological study is needed down the line. Other companies monitor at random, because workplace conditions or the work process has changed. Some companies launch monitoring programs because there was a worker complaint and OSHA subsequently mandated the sampling.
Many times, sampling occurs because a process has changed, a new process has been implemented or there is suspicion that a substance is exceeding the worker exposure limit. Cohen recommends that companies take samples on a regular basis, although how often it is done depends on the industry itself. For example, if ionizing radiation is present in a workplace, monitoring and sampling should be done much more consistently than at a facility where the potential of exposure to harmful substances is slight.
At those companies where the potential for exposure is small, then it's advisable that companies take samples at least once a year, Cohen says.
“Personally, if I was a working at a plant and was fairly sure that the process was under control, the once a year would be probably be OK,” she states.
Take Multiple Samples
In addition to continued and regular sampling, taking multiple samples at one time is crucial in order to have a more reliable accounting for the measurements being taken. Cohen notes that some companies take one sample, which could be more costly in the long run, as discrepancies in data could necessitate additional sampling.
“It's important to take multiple samples, approximately five or six, not only in case something happens when it's wrong, but [because] you don't want to make important decisions based on one number,” she says.
Cohen says she can't emphasize enough the importance of getting accurate results. Some companies err on the side of caution by rushing to purchase ventilation systems, scrubbers and other expensive equipment aimed at reducing employee exposures. By first taking accurate measurement readings, they will know if that is a necessary expense, she asserts.
“Getting accurate measurements is really important because you want to control the environment with quantitative information,” she says. “If you don't measure, then you don't know what's there and you don't have any information.”
New Equipment Definitely Helpful
Although Cohen places heavy importance on technician training and getting accurate measurements, she acknowledges that the latest in personal and environmental industrial hygiene monitoring equipment has definitely played a role in improving workforce protections.
With smaller, cheaper instruments, employers can outfit everyone working in a plant with their own personal air monitor. Passive badge dosimeters, like those Cohen showed to the workers in China, don't require the use of a pump to pull or push gas over an absorbent. There also are special personal monitors that contain sensors that will set off an alarm if the worker moves into an area where the concentration of a contaminant goes above a preset level.
Now, pumps can self-record a lot of the information that once had to be input into the device, such as the time the sampling started, if there was disturbance in the flow rate and the name of the worker and his shift number, as well as the time the sampling ended.
There also are technologically advanced monitoring systems that can be left unattended for lengthy periods of time. According to Cohen, they are too large in size to conduct personal sampling, but are perfect if an industrial hygienist wants to monitor an entire room, for example.
Although advances in industrial hygiene monitoring equipment have made it more affordable and easier to use, Cohen cautions employers not to dismiss the importance of having experienced personnel, such as an industrial hygienist or safety manager, administer the program, of which monitoring is one part.
“Someone has to make sure that things are working right,” she states.