3D Printers

3D printers.
The best practice for ventilation is to enclose 3D printers and exhaust emissions directly outside of the building.

Three dimensional (3D) printers are a great educational tool. They provide rapid prototyping and the ability to create small-scale manufacturing for various lessons in science, technology, engineering, math, and art. Although useful, 3D printers produce hazardous byproducts including fine and ultra-fine particulates, volatile organic compounds, and heavy metals.

When using 3D printers, required safety precautions protect students from inhaling hazardous particles and chemical vapors and to avoid physical hazards such as burns, cuts, and pinches. The State Board of Health Rule for Primary and Secondary Schools, WAC 246-366-080, requires 3D printers to have local mechanical exhaust ventilation. Models with HEPA (high-efficiency particulate air) and charcoal filters will help reduce hazards but or are not sufficient under the code.

A recent National Institute of Safety and Health (NIOSH) publication evaluated the hazards associated with using different 3D printers and recommended ways to minimize exposure to these hazards: Approaches to Safe 3D Printing: A Guide for Makerspace Users, Schools, Libraries and Small Businesses, CDC (PDF). This document focuses on the safe use of fused filament fabrication (FFF) 3D printers (functionally similar to fused deposition modeling, or FDM printers), which are most common in K–12 schools.

Recommendations

3D Printer and Filament Selection

  • Select a fully enclosed printer for protection from particulate, chemical, and physical hazards.
  • Consult your Chemical Hygiene Officer and Plan when selecting a printer style. Consider handling, storage, and disposal requirements for chemicals that will be used.
  • Select a printer that can be used with polylactic acid filament (PLA). PLA is a biodegradable plastic made from natural substances including sugar, corn starch, or sugar cane. PLA filaments:
    • Typically have the lowest particle emission rate of all filaments.
    • Can print at a low temperature and don’t require a heated bed, which is a burn hazard.
  • If PLA cannot be used in the application, consult the NIOSH publication for information regarding the relative health hazards of other filaments. Where emissions data are available for feedstocks of varying color and materials, choose materials producing fewer emissions.

3D Printer Setup

Printer setup includes selecting the proper location, establishing appropriate ventilation, and placing appropriate signage to provide visual reminders of safety practices.

Printer Location

  • Set up the 3D printer in an area away from student desks or main workstations. This limits the time students spend near running 3D printers.
  • Set up the 3D printer near a fire extinguisher.
  • The printer must connect to an appropriately grounded outlet.

Printer Ventilation

Safe use of 3-D printers requires effective ventilation. Here are ventilation options listed in order of preference:

  • Place the 3D printer inside an enclosure that captures emissions and exhausts them directly outside of the building.
  • Place the 3D printer as close as possible to a local exhaust hood that exhausts directly to the outside. Use a smoke tube or other visual means to ensure that the exhaust hood can capture emissions coming from the printer. Also ensure that the room receives a minimum of six air changes per hour.
  • When multiple printers are in use and it is impractical to use fume hoods, place 3D printers in a separate room with a closing door that is under negative pressure relative to adjacent areas. This room should receive at least six air changes per hour and be exhausted directly outside.

Printer Signage

Post appropriate signage and other visual cues that provide safety reminders to users. Post signs in a location directly visible to a person approaching the printer, on the front of the enclosure if possible. Signs should include:

  • Bulleted rules and procedures for safe usage.
  • Identification of and warning about hot surfaces.

3D Printer Operation

To safely use a 3D printer:

  • Conduct safety training prior to use. Training must include safe operating procedures and a discussion of potential hazards, including a review of the safety data sheet(s) for all products associated with printer use.
  • The classroom instructor should conduct a pre-use printer safety inspection.
  • Do not stand near or hover over the 3D printer when it is running.
  • Use a removable print surface set with painter’s tape or a glue stick for easy removal of completed objects. This can eliminate the need to use a sharp tool or blade for project removal.
  • Ensure that only classroom instructors or maintenance workers are authorized to complete routine maintenance or cleaning due to the potential for chemical exposure.
  • Allow only certified professionals to service the 3D printer.
  • Select the lowest temperature appropriate to filament materials being used to prevent unwanted emissions.
  • Do not attempt to defeat safety interlocks or other safety features.
  • Avoid touching the heater block, nozzle, heated print bed, and motors. They become hot quickly after the printer is turned on and can cause burns if touched.
  • Do not open the 3D printer cover once a project starts.
  • Do not eat, drink, chew gum, or touch your eyes, nose, or mouth when near or using a 3D printer.
  • Wash hands thoroughly after use.

Post-Printing

Post-printing work activities can also create exposures to physical hazards, chemicals, and particulates. These exposures can be minimized using the following practices:

  • Keep the printer enclosure or room shut for 20 minutes after printing is complete before opening to provide additional removal of emissions.
  • Before removing a project, ensure the 3D printer has cooled to avoid touching hot surfaces.
  • If using a scraper blade or another sharp removal tool, always scrape away from your body and hands and use cut-resistant gloves.
  • Use a wet towel to clean work surfaces. Sweeping or brushing will cause particles to go into the air and be inhaled.
  • If processing includes use of solvents or other chemicals or involves grinding, these activities should be conducted within an exhausted enclosure. Before purchasing or new uses of chemicals, consult your Chemical Hygiene Officer and Plan for proper handling, storage, and disposal.
  • Use a high efficiency particulate air (HEPA) filter-equipped vacuum to clean the 3D printer area to prevent distributing settled particulates into the air.
  • Wash hands thoroughly after use.

 

Content Source: School Environmental Health and Safety Program