January 17, 2014
Those freshly washed shop towels you may be using to clean your hands in the workplace might be doing more harm than good. A recent study shows just how contaminated these towels can be.
A peer-reviewed study conducted in 2013 by Gradient, an environmental and risk sciences consulting firm, concluded that U.S. and Canadian manufacturing workers who use laundered shop towels may be exposed to lead and other metals.
Research Scientist Tim Reader, of Kimberly-Clark Professional, the company that funded the research, recently participated in a Q&A with thefabricator.com about the study and its findings.
Reader: As a company dedicated to helping other organizations create safer, healthier, and more productive workplaces, Kimberly-Clark Professional is continuously looking for ways to help our customers improve their workplace environments. We have worked with Gradient, a nationally recognized environmental and risk sciences consulting firm, since 2003 to help us better understand the hidden hazards related to use of laundered shop towels.
Millions of workers across a variety of manufacturing industries use shop towels every day. After use, the towels are taken to an industrial launderer, which washes them and then ships them back out to customers, typically at other companies, for reuse. Shop towels are used for everything from process wiping, such as cleaning parts or spills, to personal wiping, like wiping hands, faces, and necks. The majority of shop towel users report hand wiping among their top uses for the product.
When we became aware of the potential for these “clean” shop towels to still contain heavy metal residues, even after the laundering process, and observed the use of these towels for personal wiping, we began working with Gradient to better understand the potential health-associated risks to workers of using laundered shop towels.
Reader: One hundred percent of laundered shop towels tested—these were towels that had been delivered to customers and were presented as ready for use—were contaminated with lead and other heavy metals. Based on the exposure assumptions employed in the study and the results from the towels tested, a worker using a typical number of laundered shop towels each day—an average of 14—may ingest an amount of lead that is 400 times higher than the health-based criterion for reproductive effects set by the California Environmental Protection Agency (CalEPA) and more lead than that described by the U.S. Environmental Protection Agency's (EPA) action level for drinking water (Figure 1).
Additionally, the worker may be exposed to aluminum, cadmium, cobalt, copper, and iron at levels exceeding intakes associated with drinking water standards set by the U.S. EPA and other toxicity criteria set by the EPA and the Agency for Toxic Substances and Disease Registry (ATSDR). Workers with high-end exposures may be exposed to lead at levels up to 1,170 times higher than the CalEPA criterion for reproductive effects and 19.5 times more than the amount associated with the EPA action level for lead in drinking water.
Reader: It is noteworthy that the issue has not diminished over the course of time. If anything, the problem of metal exposure due to shop towel use may have worsened because workers report using more laundered shop towels today than they did 10 years ago. The first study, which was conducted by Gradient in 2003, found a minimum usage by workers of 2.5 towels per day. In 2013 users reported a typical usage of 14 towels per day on average, with high-end use of 20 towels per day. With these higher use numbers, there is potential for a worker using just three towels per day to be exposed to more lead than associated with the EPA drinking water limit.
Additionally, the study points out that 24 of the 29 metals tested appear at least 90 percent of the time across the towels tested. No towel was found to be free of lead, cadmium, cobalt, copper, iron, molybdenum, nickel, and other metals. Since it is unlikely that many, if any, industries use such a wide array of metals in their processes, it is possible that this distribution of metals is due to cross-contamination through shared towels or possibly the laundering process. To the worker, this means an unintended, invisible exposure hazard may be introduced into their workplace. Since the metals cannot be seen or otherwise easily detected, it is not possible to identify the hazard without testing.
Reader: To date there has been no human health study that looks at the effects of using shop towels over a long period of time. It often takes decades of research to link contaminant issues to health effects. However, even without long-term studies completed, some workers are concerned about potential health issues related to shop towel use.
Kimberly-Clark Professional worked with Harris Interactive in 2012 to conduct a survey of U.S. manufacturing and transportation workers and learned that nearly four of every five manufacturing and transportation workers want shop towels banned if they are not completely free of hazardous materials. Eighty-five percent said they would ask their employers for an alternative.
Reader: We do not have this information available currently.
Reader: Based on the results of the Gradient study and the current laundering processes that exist within the industry, we are not aware of a better or different way to properly launder shop towels so that they are 100 percent clean or do not pose any risk to the user.
Reader: Disposable shop towels are intended to be used by a single worker, who would be knowledgeable about the substances he or she introduced to the towel when using it for wiping tools or spills.
Reader: While the most common objection to switching from laundered shop towels to the alternative is the change itself, at the end of the day, it’s difficult for any employer to find a downside to switching that outweighs the potential health risks to employees. Anecdotally, we’ve received feedback from a number of those customers initially resistant to change that they would never go back to laundered towels now that they have made the switch.
Reader: Only relatively recently have laundered shop towels been identified as a potential source of heavy metal exposure in the workplace. Now that the original finding has been repeated and the problem appears to be getting worse, awareness of the issue may prompt response by OSHA in the future.
A company can be penalized by OSHA if the workplace exposure to heavy metals exceeds established permissible exposure limits (PELs). There are established PELs for airborne metal dusts to address the inhalation exposure concerns. However, to date there are no such regulatory guidelines or exposure limits to address employee exposure to heavy metals through skin contact and unintended ingestion. Like for many workplace hazards, awareness is the first step in determining appropriate response and the means to remove or mitigate the hazard.
Reader: Kimberly-Clark Professional is working closely with its distributor partners to educate our customers about the presence of heavy metals on shop towels. To help companies avoid unnecessary heavy metal exposure, we also offer the “What’s in Your Shop Towel?” testing program, which allows a company to select samples of their laundered shop towels and send them to a third-party testing facility with expertise in metals analysis. In addition, we are in ongoing conversations about the outcomes of the Gradient studies with various worker groups to offer education and to gauge their interest in this unnecessary exposure to metals in the workplace.