3D printing process emissions may cause ‘strong irritation’: study

Marietta, GA — Emissions from stereolithography 3D printing could “present a strong irritation response among those exposed” and be hazardous to human health, according to a recent study.

Researchers from Chemical Insights, an institute of Underwriters Laboratories Inc., measured emissions from an enclosed 3D printer that uses SLA printing technology, shining ultraviolet light on a vat of photopolymer resin and hardening the resin to create objects.

SLA differs from another printing technology previously studied by the organization – fused filament fabrication – and is becoming increasingly common as the popularity of 3D printing remains on the rise, Marilyn Black, the study’s lead researcher as well as officer and technical advisor at Chemical Insights, told Safety+Health.

During the SLA printing process, the researchers detected 40 volatile organic chemicals, which were signified in part by “a pretty significant odor,” Black said. Seventy-six additional VOCs were detected during post-processing operations involving washing and curing.

Overall, the three stages produced 45 “chemicals of concern,” substances included in health-related regulations and guidance. Formaldehyde, a known human carcinogen, was detected during printing, washing and curing. The researchers note that although the emission rates and estimated office exposure levels for the chemicals of concern registered below what is listed in regulations, the chemicals nonetheless could trigger an irritation response in the skin and respiratory system. The longer a person is exposed, the more sensitive they may become.

“Kind of like poison ivy,” Black told S+H. “You may not react to poison ivy initially, but after you’ve been exposed for a while, then you get highly sensitized to it and can’t even get around it.”

NIOSH offers best practices for protecting workers from possible 3D printing hazards, including:

• Use materials with lower chemical emissions.
• Use enclosures for 3D printers and ventilation to capture emissions.
• Reduce time spent near the printer while it’s running.
• Wear appropriate personal protective equipment, such as safety glasses, gloves and lab coats.
• Limit equipment access to trained or authorized personnel.

“When we’re talking about these sorts of emissions, our position always is that ventilation is the best mitigation source there is,” Black said. “As much air as you can get diluting these emissions and flushing them out, or having direct exhaust systems that pull the emissions and exhaust them out of the building so they can’t get into the air for people to be exposed. Taking those control measures is extremely important in protecting the workers.”