Canadian Occupational Safety

26 Canadian Occupational Safety | www.cos-mag.com VENTILATION AND FILTRATION Some 3D printer manufacturers have built controls into the equipment designed to limit particle emission. These controls include covers, full enclosures and filtration systems. Some printers are entirely contained within an enclosure equipped with a re-circulating filter. One company says the filtration system attached to its printer enclosure captures 85 per cent of emissions. Safety managers should always take advantage of these manufacturer-supplied controls, says Neil Johnston, interim president and CEO of the Mani- toba Lung Association in Winnipeg. If the printer comes with an enclosure, it should not be modified. "Printers usually come in a plastic housing with a hatch that you would access. So those should be maintained and kept in good condition. Make sure the seals are still there and don't bypass any safety guards — like taking the safety guards off any kind of saws. The safety cabinet needs to be kept in place and maintained or enhanced," he says. Workplaces should also reduce emissions by good localized ventilation, Johnston adds. A good high efficiency particulate air (HEPA) system with activated carbon or similar type of filter should be placed near the printers. Make sure printers are operated in a well-ventilated room and install direct ventilation to draw emissions away from the printers and out of the room. Along with using manufacturers' controls and installing good ventilation, the National Insti- tute for Occupational Safety and Health (NIOSH) in Atlanta recommends these ways to reduce emissions: • Maintain a distance from the printer to mini- mize breathing in emitted particles and choose a low-emitting printer and filament when possible. •Avoid staying in the same room with a printer for long periods of time. • Turn off the printer if the printer nozzle jams and allow it to ventilate before removing the cover. • Use engineering measures first, such as manufac- turer-supplied equipment and proper ventilation, then use materials with lower emissions. • Wear protective equipment such as respirators if necessary. Managers must also provide proper training, Stevenson says. Workers should be aware of the respiratory hazards created by 3D printers and know how to avoid them. AIR MONITORING According to industry recommendations, work- places using 3D printers should have an air monitoring system to identify the types of emis- sions the printers are producing and what health risks the emissions may pose to workers. While the air around 3D printers should be mon- itored for emissions, the cost may be too high for most companies, Stephens says. An employer who needs "speciated VOC" data, that is, data that iden- tifies the specific VOCs in a sample, would probably have to pay about $400 per sample for an analysis. The instruments that measure the ultrafine parti- cles (UFPs) generally cost at least $6,000 to $7,000. The cost is high because of the small size of the particles, he says. They cannot be measured with the cheaper devices that measure larger particles. A cheaper option is to do real-time VOC measurement using an instrument such as a photo- ionization detector (PID). The device, which costs about $1,000, is commonly used by occupational health and hygiene managers, Stephens says. While the device will not identify the specific VOCs present in emissions, it will provide the user with a number indicating the total VOCs (T VOC). In their research, Stephens and his team used a PID to measure emis- sions produced by a printer already tested and identified as containing styrene. "If you know what your printer is emit- ting, you could technically use a cheaper instrument like that and get some idea of the VOC concentration. The instrument won't tell you what the VOC is, and so without knowing what the VOC is, it doesn't really help you because it might be something harmless," he says. RESPIRATORY PROTECTION If workers are accessing the printer cabinet regularly, Johnston says, they should wear respiratory protection. "And if the local ventilation is inadequate, they need to have a particulate respirator. That's the last step after having engineering controls," he adds. Whether workers need to wear respiratory protection depends on the type of filament being used in the printing process, Stephens says. Current research shows that ABS and nylon filaments have high emissions of gases or particles, while PLA (polylacticacid) fila- ments generally do not. While companies are advised to operate 3D print- ers in a well-ventilated space, they should be aware that workers situated near the printer for a long time still need to wear some PPE. The main thing here is to make sure the PPE contains a good, combined particle and gas filter, Stephens says, adding 3D printers should be thought of as another shop tool. "There are a lot of shop tools that, when they're being used, we generally recommend some kind of protection, whether it's respiratory masks for sawing or cutting wood or doing laser cutting. I think 3D printing should be lumped into one of those categories — even though it feels a little like a laser printer — particularly if a worker is suscep- tible (to respiratory health problems)," he says. INTRODUCE A HEALTH PROGRAM The employer or safety manager at a workplace using 3D printers should put in place and main- tain a health program to ensure emissions are not harming workers, Johnston says. As with any dust and particulates exposure program, it is good to start with a health questionnaire to determine workers' respiratory health. If any employee has problems, that person might have to go for spi- rometry (lung-functioning testing) or a chest X-ray. Then, following a good particulate and dusty envi- ronment protocol, the manager should check from time to time to see whether there are any changes in the worker's respiratory health. Any workers who have allergies, asthma or other chronic lung conditions will be at risk, and added measures may need to be taken. "People may already have lung problems; those will be exacerbated and those need to be managed. But there are also people who, on exposure to this, may develop lung problems. So there should be some kind of monitoring program as well," Johnston says. Today, 3D printing is still fairly new and manu- facturers have not paid adequate attention to safety hazards, Stevenson says. "It's a very competitive space. Right now, there are a billion companies, and we don't know which will survive and become the Fords and GMs of the future. They are typically chasing the most promi- nent aspects in the minds of the customers, which are cost and speed and types of material that are available. Safety is almost never mentioned as an issue," he says. Stephens agrees most manufacturers are not focused on developing technologies to reduce emissions. While there are currently many groups conducting environmental and health studies on 3D printers, he says, it would be better if manu- facturers focused more on coming up with ways to protect workers' health. "I'd rather us not spend resources on measuring emissions," he says. "I'd rather see this pretty clever group of people — who figured out how to print things — to just say this is probably a problem. Let's handle it." Linda Johnson is a freelance journalist based in Toronto. There are a lot of shop tools that, when they're being used, we generally recommend some kind of protection, whether it's respiratory masks for sawing or cutting wood or doing laser cutting. I think 3D printing should be lumped into one of those categories. LOOKING FOR A SUPPLIER OR VENDOR? Visit hrreporter.com/hr-vendors-guide

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