Wood dust is created when power tool machines like band saws, belt sanders, and table saws and hand tools like hand saws, planes, and chisels are used to cut or shape wood. Wood dust is created during all stages of wood processing, including sawing, routing, sanding, and other operations. Workers also may be exposed when the wood dust is airborne, such as when removing dust from furniture, doing maintenance activities, or when cleaning equipment.

Individuals including teachers of STEM (science, technology, engineering, math), technology and engineering education, makerspaces, and physics who use these power tool machines and/or hand tools to cut or shape wood as part of their curriculum activities will be exposed to wood dust. When that wood dust is inhaled, it is deposited in the nose, throat, and other airways, resulting in the potential health and safety issue. According to the National Cancer Institute, “strong and consistent associations with cancers of the paranasal sinuses and nasal cavity have been observed both in studies of people whose occupations were associated with wood-dust exposure and in studies that directly estimated wood-dust exposure.” (See this website.)

The problem for teachers is while the students come and go, these teachers stay for years and are exposed to the wood dust if their laboratories lack appropriate engineering controls.

Wood dust is considered carcinogenic to humans (Group 1) according to the International Agency for Research on Cancer (IARC). IARC states that wood dust causes cancer of the nasal cavity (nose area) and paranasal sinuses (spaces in and around the nasal cavity) and of the nasopharynx (upper part of the throat, behind the nose). Wood dust also can be associated with toxic effects; irritation of the eyes, nose, and throat; dermatitis; and respiratory system effects, which include decreased lung capacity and allergic reactions.  In addition to health issues, production of wood dust also can be a major safety concern because it can cause a fire or explosion if airborne and exposed to active flames or sparks.

In addition, according to the National Institutes of Health (NIH) Report on Carcinogens, 14th Edition, “Wood dust is known to be a human carcinogen based on sufficient evidence of carcinogenicity from studies in humans.” (See the Wood Dust profile.) The level of dust exposure deposited within the respiratory airways is dependent on the size, shape, and density of the dust particles, in addition to the strength (turbulence and velocity) of the airflow. For example, use of handheld electric sanders has been identified as a particularly dusty process that leads to high levels of dust exposure.

Legal safety standards that help protect workers in situations of wood dust exposures are addressed in specific Occupational Safety and Health Administration (OSHA) standards for general industry. For example, the preamble of OSHA Hazard Communication Standard (HCS) states, “wood dust is a recognized health hazard, with exposure limits recommended by the American Conference of Governmental Industrial Hygienists (ACGIH) to control employee exposure to the substance.” Under the provisions of the HCS, this means that wood dust is considered a hazardous chemical [paragraph (d)(3)(ii)], and therefore subject to the requirements of the rule including material safety data sheets and training. For specific OSHA standards and documents related to wood dust, see https://www.osha.gov/wood-dust/standards.

According to OSHA, engineering controls and personal protective equipment (PPE) are two methods used for controlling wood-dust exposure. Engineering controls are the preferred approach. This normally includes an exhaust ventilation system with collectors placed at points where dust is produced. PPE is a short-term solution to wood dust exposure. Respirators may be worn to remove hazardous particulates (dusts) and gases. The selection of appropriate respirators requires a thorough knowledge of the workplace, the potential chemical contaminants, and their concentrations. The use of respirators also requires implementation of a respiratory protection program. This OSHA site contains numerous specific resources to help reduce wood dust exposure.

The Canadian Centre for Occupational Health and Safety has a fact sheet titled “Wood Dust—Health Effects.” It has the following list of safety protocols for teachers to help control their exposure to wood dust:

• Know which type of wood is being used and all hazards associated with that wood. Substitute with another type of wood with no or fewer known health effects, where possible.
• Reduce dust generation. For example, reduce the need to cut or shape the wood.
• Use an appropriately designed industrial ventilation system, including local ventilation exhaust and the use of high-efficiency particulate (HEPA) filters. The design of the ventilation system will depend on the equipment being used (sanders, shapers, routers, saws, etc.).
• Use on-tool extraction systems when safe to do so.
• Keep tools and blades sharp. As tools dull, they may release more dust into the air.
• Be aware that significant exposure can happen when cleaning (e.g., emptying dust bags) or maintaining equipment.
• Practice good housekeeping. Keep surfaces and floors clear.
• Use cleaning methods that reduce re-introducing the dust into the air. Use wet clean-up methods with appropriate slip hazard signage (e.g., wipe surfaces with a wet rag or mop), or use a vacuum with a HEPA filter.
• Read, understand, and follow health and safety information on the safety data sheet (where available and applicable).
• Provide appropriate education and training that informs employees about the hazards of wood-dust exposure, safe work procedures, how to identify when a ventilation system is working appropriately, and the importance of control measures.
• Wear respiratory protection when appropriate.
• Use protective clothing and gloves to reduce skin exposure.
• Practice good personal hygiene (e.g., wash or shower to remove dust from skin). 
• Wash hands and face when finished with a task, and before eating, drinking, or smoking. 
• Clean clothes by washing or using a vacuum when washing facilities are not available.
• Bag and seal dust waste to prevent dust from re-entering the air.
• Do not use compressed air to blow dust off of furniture, equipment, or clothing.
• To prevent a combustible dust explosion, do not allow wood dust to accumulate, including on ledges, ceiling beams, light fixtures, hidden areas, etc.

One final outstanding OSHA resource titled A Guide for Protecting Workers from Woodworking Hazards can be found at https://www.osha.gov/sites/default/files/publications/osha3157.pdf.

If a teacher’s laboratory has either power tools or hand tools that produce wood dust, make sure the proper wood dust collection system is in place and well maintained for the health and safety of both teachers and students!

Submit questions regarding safety to Ken Roy at safersci@gmail.com or leave him a comment below. Follow Ken Roy on Twitter: @drroysafersci.