Shop towels could be exposing people to heavy metals even after they've been laundered, reports a study published in Human and Ecological Risk Assessment: An International Journal.1
"This serves as an eye-opener," says Wagish Yajaman, a technical specialist at Workplace Safety & Prevention Services. "Exposure to hazardous substances is a bigger issue than people realize."
People use shop towels to wipe oil, solvents, and other chemicals from machinery, work surfaces and their own hands. "I've even seen towels used as protective equipment," says Yajaman. "One company with a wet grinding operation used a rag on the machine surface to prevent particulates from spraying onto the work surface. Then they'd send this rag to the laundry with all the other towels."
Any of these activities could transfer contaminant residue from towels to workers, who risk exposure to the residue through absorption, inhalation, ingestion, or injection.
For their study, researchers collected laundered towels from 38 U.S. and 16 Canadian companies and estimated exposure to 28 different metals, including aluminum, beryllium, cadmium, cobalt, copper, iron, and lead. Exposure estimates were based on metal concentrations found in soiled and laundered towels, as well as exposure modelling.
The participating companies belonged to a wide range of industry sectors, including automotive, aviation, chemical manufacturing, electronics, food and beverage packaging, metal manufacturing, printing, and others.
How to protect your workers
"People need to understand that sending towels for laundering may not remove all contaminants, and so may expose the next person using the towels to harmful substances," says Yajaman. "You can't assume they come back 100% clean."
The study suggests that workplaces decrease or eliminate hand-to-mouth transfer of residue by providing
adequate hand-washing facilities and/or
personal protective equipment such as gloves or barrier creams.
Yajaman encourages workplaces to go a step further and consider where potential exposures may occur. He suggests
reassessing how they are using these towels. Is it just for wiping hands? If it's for cleaning surfaces or equipment, is there a better way to do it?
reviewing cleaning and disposal practices. Are you using appropriate methods? Are there better methods you could use?
exploring possibilities of eliminating exposure. For example, is there a way to prevent leaks or contain the particulates generated by grinding that are now being picked up by the towels?
encouraging workers to wash their hands rather than wiping them on a towel.
"If you're not sure what substances workers may be exposed to, check your material safety data sheets (MSDSs)."
The Textile Rental Services Association, an international organization representing companies that supply laundered garments, uniforms, linens, floor mats, towels and other products, has suggestions for member firms that could also apply to their customers:
develop and implement policies and procedures that address processing, use, and handling of soiled shop towels. These policies and procedures should include the chemicals and other contaminants that you anticipate on the soiled textiles.
wear personal protective equipment such as gloves and safety glasses when handling soiled shop towels
wear slip resistant shoes
who handle soiled shop towels wash their hands and face prior to eating, drinking, smoking or performing any other activity that could involve hand to face contact.
keep soiled towels away from open flames and all other goods.
store towels soiled with flammable material in a self-closing flammable material storage container.
How WSPS can help
Workplace Safety & Prevention Services' technical consultants can help you identify and assess potential exposures to hazardous substances arising from your workplace practices. Assessment methods include air sampling, and surface wipe and hand wipe sampling.
Check out additional WSPS resources related to occupational hygiene and exposure to chemicals, physical agents and biological hazards.