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Additive Manufacturing: 3D Printing

3D Printing is the fabrication of objects through the deposition of material using a print head, nozzle, or another printing technology. The term is often used interchangeably with additive manufacturing.

 

Types of 3D Printers

  • Stereolithography (SLA)

  • Digital Light Processing (DLP)

  • Fused Deposition Modeling (FDM)

  • Selective Laser Sintering (SLS)

  • Selective Laser Melting (SLM)

  • Electronic Beam Melting (EBM)

Many of these printers and filaments have hazards associated with them that users should know, understand, and be trained to handle.

 

There are many different hazards associated with 3D printers or any additive manufacturing process. These hazards include:

  • Hazardous vapors and gases emitted during the printing process. (i.e. ultrafine particles and volatile organic compounds)

  • Hot surfaces – print head and UV lamps

  • High Voltage – UV lamp connector, electric outlet safety certified and ground wire

  • Moving parts – printing assembly

  • Metals – oxygen monitoring factors, static electricity

  • Chemical storage, use, and waste (hazardous waste)

Acrylonitrile Butadiene Styrene (ABS) and Polylactic Acid (PLA), commonly used plastic filaments, have been found to release ultrafine particles and volatile organic composed when heated. Volatile organic compounds (VOC) are organic chemicals that have a high vapor pressure at room temperature. The high pressure nature means that large numbers of molecules are able to evaporate and enter the surrounding air. Emission rates of total ultrafine particles have reached 20 billion particles per minute utilizing PLA, and 200 billion particles per minute when utilizing ABS. There are differences in toxicity because of differences in chemical composition of the feedstock and ultrafine particle byproducts.

ABS, PLA, AND NYLON CAN BE A SOURCE OF DANGEROUS VOCS SUCH AS STYRENE, BUTANOL, CYCLOHEXANONE, ETHYLEBENZENE AND OTHERS. HEALTH EFFECTS FROM VOC EMISSIONS INCLUDE EYE, NOSE, AND THROAT IRRITATION, NAUSEA, AND ORGAN DAMAGE.

Metals also have health and safety concerns.  Oxygen monitoring, fire hazards, and inhalation and exposures hazards are prevalent in areas where powdered metal is used in 3D printers. In areas where there are no oxygen monitoring and limited means of ventilation, the use of argon and nitrogen could create an oxygen deficient atmosphere as it displaces oxygen without warning. The results would be the same as if carbon monoxide was present.

Static electricity also creates a fire hazard when introduced to powdered metals. When introduced together, the powdered metals can burst into flame with the slightest ignition. It is imperative to ensure a static free environment in spaces where metal 3D printers are housed and operational.  It is also crucial to understand the characteristics of metal fires, and how to properly use a Class D fire extinguisher. Any other class of fire extinguisher, used improperly, could allow the fire to spread.

Inhalation health hazards are present when manually restocking the powdered metal through open canisters, handling finished parts that may have some loose metal powders, and/or all other handling of the powdered metal. Inhalation of powdered aluminum has been known to cause serious respiratory and neurological health effects if enough is inhaled.

 

  • Always use the manufacturer’s supplied controls (full enclosure appears to be more effective at controlling emissions than a cover).

  • Use the printer in a well-ventilated place, and directly ventilate the printer. Task Ventilation may be useful for some styles of 3D printing. Contact AU Facilities to help determine proper ventilation for printing area.

  • Maintain a distance from the printer to minimize breathing in emitted particles, and choose a low-emitting printer and filament when possible.

  • Turn off the printer if the printer nozzle jams, and allow to it to ventilate before removing the cover.

  • Use engineering measures first, such a manufacturer-suppled equipment and proper ventilation, then use materials with lower emissions.

  • Ensure a risk assessment or hazard analysis has been conducted as it relates to: printer use, hazards associated with media/printing materials, servicing and maintenance, and prolonged exposure.

  • Consult the safety data sheets (SDS) of printing materials. Follow manufacturers safety recommendations regarding use, storage, personal protective equipment, waste, etc. detailed in SDS.

  • Provide safety training to individuals that work with 3D printers in the following areas:

    • Chemical safety specific to chemicals used during 3D printing process.

    • Current and safe operation of the 3D printer.

    • Personal protective equipment (PPE) per 3D printer and chemical usage.

      • PPE will be suggested by 3D printer manufacturer and SDS.

      • NIOSH approved respirator usage is suggested to eliminate inhalation hazards when working with powdered metals.  Respirator use requires adherence to AU Personal Protective Equipment Policy (create hyperlink here).

      • When utilizing metal printers, additional PPE is recommended; such as, fireproof lab coat, eye protection, and 5 mil nitrile gloves(product handling)

  • When using metal materials keep workspaces free of any static electricity.

    • Ensure all machines are grounded by using anti-static mats;

    • Having statically grounded vacuum cleaners;

    • Covering the floor with an anti-static coating;

    • Requiring the use/wear of anti-static shoes.

  • Areas that utilize powered metals along with argon and nitrogen should have an O2 monitoring system.

  • Do not open 3D printer covers once a print job is underway.

  • Equip the facility with a Class D fire extinguisher and train on proper use. (Metal usage)

  • Handle uncured printing materials with neoprene or nitrile gloves.

  • For print processes that use an alkaline bath to dissolve support material, provide an emergency eye wash station in the immediate vicinity of the work.

  • Wear eye protection around liquid materials that can splash.

  • Use solvent-absorbent pads for spills of printing material.

  • Do not leave print jobs unattended. For extended print times, monitor print through cameras or designated/authorized person to monitor through out print.

  • Keep model and support materials away from areas where food and drink is stored, prepared, or consumed.

  • Safety signs and labels posted on and nearby printers should warn of emissions and hot surfaces. HVAC controls for ventilation should indicate the requirement for indoor air quality. Signs should indicate the location of eyewash stations, fire extinguishers, feedstock, and chemical storage, and clean up supplies. In labs that employ anti-static measures labeling equipment with a label that has anti-static properties will help avoid static buildup.

  • Install floor marking tape around printer or alkaline baths indicating hazardous areas to students and staff.

  • Spill control and containment tools to help prevent a chemical spill from spreading and ease clean-up.

  • Ensure that all chemicals are stored properly.

* General safety practices were collected from recommendations published by Carnegie Mellon University, University of Florida, University of Vermont, Georgia Tech, National Institute for Occupational Safety and Health (NIOSH), and the UL Additive Manufacturing Competency Center at the University of Louisville.

 

3D Printer Information Packet

3D Printer Registration Form

3D Printer Hazard Assessment Form

 

For help with any of the aforementioned information, Auburn University Risk Management and Safety can help your department with identifying appropriate safety measures for each of your departments’ processes.