The Kimberly-Clark Professional-commissioned analysis, Evaluation of Potential Exposure to Metals in Laundered Shop Towels, found a worker using an average 14 laundered shop towels a day may ingest an amount of lead 400 times higher than the health-based criteria for reproductive effects set by the California Environmental Protection Agency (CalEPA) and more lead than that associated with the EPA’s action level for drinking water.
That same worker may be exposed to aluminum, cadmium, cobalt, copper and iron at levels exceeding intakes associated with drinking water standards and toxicity criteria set by the EPA and the Agency for Toxic Substances and Disease Registry.
While regulators have long studied and regulated metals that may be consumed in drinking water or inhaled, worker exposure to chemicals and metals through the inadvertent transfer of substances from hands to mouth is rarely addressed in occupational literature, says Gradient.
Gradient used data on transfer of residues to hands, the number of towels workers used daily, and an approximation of the percent of towel surface area that came into contact with the hand to estimate worker exposure levels.Transfer models allowed Gradient to estimate the movement of metals from towels to hands and then the mouth. A scanning electron microscope imaging was used to find the presence of heavy metal particles, which were too small to see with the naked eye, on the surface of the laundered shop towels.
The environmental and risk science consulting firm’s study builds on a 2003 analysis showing showing that shop towels retain measurable levels of metals after commercial laundering and extends the findings presented in 2012 at the annual Society of Toxicology conference.
A similar Gradient analysis presented last year collected data from laundered shop towels submitted by 26 North American manufacturing companies to an independent testing lab.