New Study Raises Concerns Over Safety Of Laundered Shop Towels

Independent research supports findings of original 2003 study that American workers are being exposed to harmful chemicals and metal residues at potentially hazardous levels by using laundered shop towels

CARY, N.C. — July 20, 2011 — A recently released report analyzing the potential risks for workers using laundered shop towels finds that the situation is just as potentially hazardous – and in many cases potentially more hazardous – than when a similar study was completed nearly a decade ago.

The increased use of laundered shop towels on the job, along with higher detected concentrations of certain substances, and the availability of additional toxicity criteria resulted in more “toxicity criteria exceedences” than were found in the earlier study.   Cambridge, MA-based environmental and risk science consulting firm Gradient concluded that workers using laundered shop towels could be exposed to levels of contaminants that exceed regulatory agency guidelines.  Based on certain intake pathway assumptions, this exposure could impact their long-term health. Towels are presumed by workers to be clean and are frequently used for personal wiping like hand wiping or other contact with bare skin such as blotting perspiration.

Released earlier this month, “Evaluation of Potential Exposure to Metals in Laundered Shop Towels,” found that “clean” shop towels sampled from 26 different industrial sites had significantly higher concentrations of metals and chemicals than in 2003. The paper was authored by respected researchers Leslie A. Beyer MS, Grace Greenberg MPH, and Barbara D. Beck PhD, Gradient.

The researchers concluded that even after commercial laundering, the towels studied retain elevated levels of metals and oil and grease, which could result in worker exposures that exceed regulatory agency guidelines. Additionally, the laundered shop towels may unexpectedly introduce new metals that are not otherwise in a facility. 

“The findings of these researchers, building on the original work conducted in 2003 by Gradient, provides the second study of its kind confirming the potential health hazards of exposure to metals risked by using laundered shop towels,” comments Rory Holmes, President of INDA, Association of the Nonwoven Fabrics Industry, Cary, N.C., a trade association that represents the entire value chain of the nonwoven fabrics industry.

“When Gradient analyzed laundered shop towels in 2003, they found that significant amounts of lead, cadmium and antimony could be ingested by workers who use just 2.5 towels per day,” Holmes points out. “The recently released study shows that workers are risking exposure to even greater amounts of these metals, as well as several additional substances that were not identified the first time around. It is imperative that the users of these towels and their employers take a serious look at their continued usage.”

Among the findings of the Gradient report:

• A greater number of metals exceed health-based exposure criteria than was the case when the original report was issued in 2003, based on assumptions of typical pathways to ingestion. In fact, a worker using a typical number of laundered shop towels a day (12) could be exposed to levels of antimony, beryllium, cadmium, cobalt, copper, lead and molybdenum that are higher than health-based guidelines set by regulatory agencies.
• The tested towels are “dirtier” in terms of their metal and chemical residues than they were during the original study. The concentrations of six metals – aluminum, barium, calcium, copper, magnesium, and sodium – were found to be significantly higher than towels tested in the 2003 Gradient study.
• More metals were detected more often and a wide variety of heavy metals were commonly found on the shop towels tested. On more than 90% of the towels tested, 26 different metals were found.
• The 2011 study also found that workers report using an average of 12 towels per day and may use up to 26 towels per day. The higher the number of towels used, the higher the worker exposure to the metals found in the towels.

Holmes refutes assertions that the Gradient study motives are biased. “The independent study, which was commissioned by Kimberly-Clark Professional, allowed Gradient researchers to analyze data from laundered shop towels used across various manufacturing industries, Holmes says. The towels were then submitted to an independent lab for testing. This science is established and is frequently used to assess exposure, Holmes points out, adding that the initial study in 2003 was peer-reviewed. The nonwovens industry provides products that are free of these residues and are used by men and women in the workplace every day,” Holmes says.

The National Association of Manufacturers estimates that nearly 12 million Americans, or nine percent of workers, are employed in manufacturing. Across industries – from equipment manufacturing and printing, to aviation and automotive work, to food and beverage packaging and medical device manufacturing – workers use laundered shop towels for wiping equipment, as well as their hands and faces. Industrial launderers then collect the towels from different workplaces, wash them together, and send them out again for use by the same or other businesses. 

“Manufacturers face an unexpected worker exposure issue: workers using just one or two shop towels a day may be exposed to elevated levels of heavy metals, compared to health-based exposure guidelines,” says Barbara Beck, Ph.D., DABT, principal at Gradient, who has testified before the U.S. Congress on lead toxicology issues.

“Without knowing it, manufacturing workers may be ingesting certain heavy metals at elevated levels from this unexpected source. For some of these metals, the amounts ingested may be greater than allowed in drinking water on a daily basis,” Dr. Back adds. “Because towels are used and then laundered multiple times and are often delivered to different companies each time, workers may even be exposed to metals that do not otherwise exist in their work environment.”

Download a copy of the Gradient white paper, “Evaluation of Potential Exposure to Metals in Laundered Shop Towels”.