3D Printers and Indoor Air Quality

3D Desktop Printer
MakerBot Replicator2

Ideal for rapid prototyping and small scale manufacturing, the 3D printing technology is expanding rapidly fueled by the development of low-cost desktop 3D printers.

3D printing (or Additive manufacturing) is an additive process known as molten polymer deposition (MPD) where very thin layers of thermoplastic are melted successively deposited on a baseplate by a computer controlled heated nozzle. As the thermoplastic hardens, the baseplate moves to the next layer, and the process continues until the desired 3D object is created.

There are several types of thermoplastics suitable for this process (polyvinyl alcohol - PVA, polycarbonate - PC, high-density polyethylene - HDPE) but most desktop 3D printers utilize either acrylonitrile butadiene styrene (ABS) or polylactic acid (PLA).

Acrylonitrile butadiene styrene (ABS) is a tough thermoplastic with a very good impact resistance and shock absorbance. In the 3D printing process the acrylonitrile butadiene styrene (ABS) prints at approximately 220 °C nozzle temperature and 80 °C baseplate temperature.

Polylactic acid or polylactide (PLA) is a thermoplastic derived from organic renewable sources such as corn starch and it prints at nozzle temperatures of about 180 °C and room temperature for the baseplate.

Recent studies on thermal processing of thermoplastics indicate that both gases and particles are emitted during the manufacturing processes. The main byproducts of the ABS thermal decomposition include carbon monoxide, hydrogen cyanide and a variety of volatile organics (VOC), all being well-known health hazards.

Another potential concern is the ultrafine particles (UFP), particles less than 100nm generated during the 3D printing process.

The authors of the “Ultrafine particle emissions from desktop 3D printers” study conducted a series of measurements on UFP concentrations resulting from the operation of several desktop 3D printers operating in a small office. The results indicated both ABS and PLA thermoplastics emit relatively high concentrations of ultrafine particles (UFP) and proper filtration is recommended.

UFPs are the main constituent of airborne particulate matter and due to their ability to penetrate deep within the lung and deposit in head’s airways, are a major health concern.

Quatro Air SPL-400
Multipurpose Source Capture Air Purifier

Experimental studies have shown that ultrafine particles are capable to pass through skin, enter the bloodstream from the lungs and cross cellular membranes. It was also indicated that the toxicity could increase as the particle size decreases due to increased surface area.

Even if components of certain UFPs are not very toxic, exposure to high concentrations may cause oxidative stress, inflammatory mediator release, and could induce lung disease and other systemic effects.

With a fast growing user base and sold without proper filtration, the 3D printers could expose the operators to serious health hazards.
Backed by 20 years of experience in air purification systems, Quatro Air Technologies (1.877.978.2876) offers a wide range of high efficiency source capture fume extractors designed remove airborne contaminants and create a healthy work environment.

Clean Air for the Printing Industry

Image courtesy of FreeDigitalPhotos.net

A fast-paced, deadline-driven sector, the printing industry is a major contributor to the global economy.

“Commercial printing is Canada’s longest established and most widely dispersed information technology-based manufacturing industry. Canada’s printing industry accounts for 8.11% of all manufacturing industry in the nation. In 2011 the Canadian printing industry employed 58,469 individuals. There are about 6,724 establishments across the country and which are primarily Canadian-owned.
In 2011 these employees produced over $8.4 billion worth of shipments, $918 million of which was in export sales. With a gross output multiplier of 1.65, the industry will generate an additional $5.47 billion in other sectors of the Canadian economy.” Canadian Printing Industries Sector Council

Many print shop workers face a significant risk of  injury or illness due to their constant exposure to chemical hazards involved in the printing processes such as cleaning solvents, inks, lacquers, spray powder, paper dust, ozone from the UV curing lights. Even though chemical hazards are prevalent due to the use of specific compounds, biological hazards in form of viruses, fungi, bacteria and mold have been linked to a extensive array of health issues.

Deletion fluids containing hydrofluoric acid (toxic and corrosive compound) are occasionally  used to make minor alterations to printing plates. These products are harmful if skin or eye contact occurs leading to skin burns and eye damage. Extremely dangerous if inhaled or swallowed,  the hydrofluoric acid could cause severe respiratory tract irritation.

Ozone, a gas produced during the high voltage electrical discharge in photocopiers and laser printers, is another highly toxic pollutant. In normal conditions, ozone breaks down in air rapidly, but the process can be slowed down by high humidity and temperature. Adverse health effects include eye, nose, throat and lung irritation, dermatitis, headaches and nausea, premature aging, and potential reproductive dangers. Itching, can occur on the face, neck and areas of skin exposed to ozone. When mixed with nitrogen oxide produced when there is a spark in electrostatic photocopiers. ozone can also have an effect on the central nervous system.

The VOCs (volatile organic compounds) generated during the photocopying and laser printing processes can contain traces of decane (carcinogenic), 1,1,1- trichloroethane (can cause skin irritation), iso-octane, toluene (causes fatigue, drowsiness, throat and eye irritation), xylene (can cause menstrual disorder and kidney failure), and benzene (carcinogenic and potential teratogenic).

The drums inside certain printers and copiers might contain selenium or cadmium sulphide. The hot gases emitted from these materials might  cause throat irritation and to exposed workers and short-term exposure to high levels of selenium by ingestion causes nausea, vomiting, skin rashes and rhinitis.

The health effects of carbon monoxide produced when toner (containing carbon black) is heated in poorly ventilated conditions the effects include headaches, drowsiness, faintness and increased pulse rate. Toners, a mixture of plastic resin and carbon black, are classified as a nuisance dust (mildly toxic in itself) but contains impurities known to be carcinogens.

The indoor use of propane or gasoline-fueled equipment such as forklifts has been linked to carbon monoxide exposure in workers. Carbon monoxide (CO), an odorless, colorless gas, can cause sudden illness and death when high concentrations accumulates in a contained, poorly ventilated space.

Quatro Air Technologies (1.877.978.2876 ) has served the print industry for the past 19 years, providing numerous printer manufacturers and print shops with solutions adapted to their specific needs. Visit our website for details.