Ensuring Proper Safety Measures for a Paint Booth

Q. Our business sprays solvent-based paint. What safety measures should we have in place to keep our employees safe?

A. There are many subtle hazards associated with spraying liquids, and in extreme cases, fire or explosion can occur. Creating a proper finishing environment, and keeping your booth, spray guns and filters clean, will help to ensure the safety of your technicians.

To combat many of the dangers associated with spraying liquids (whether they are solvent-based, waterborne or high solids), acquiring and using a quality, code-compliant paint booth is the first step. Paint booths provide a ventilated structure that encloses the spraying operation and confines the spread of vapor, overspray and residue, safely directing them to a filtered exhaust system. Spray booths and finishing equipment must comply with the National Fire Protection Association’s (NFPA) Class 1, Divisions 1/2 standards, which encompass many safety requirements, including capture velocity, sealed light fixtures and non-sparking components.

As with human involvement in any potentially dangerous activity, safety is paramount. When spraying liquids and solvents, the chemicals become atomized. Should a source of ignition be introduced into this atmosphere, the potential for fire is very high. By nature, liquid applications are more hazardous than powder. They may contain harmful chemicals and volatile organic compounds, and can pose a safety risk even when they aren’t being sprayed. Powder, on the other hand, can be stored worry-free and is safe to spray, as long as it isn’t inhaled and doesn’t come in contact with a person’s skin.

If you work in the finishing industry and use liquid application methods, you should take the time to become informed on the correct national and local safety standards. These standards have been written in response to events that have occurred, and should not be seen as a restriction on your business’s production or a way for agencies to impose some arbitrary rules. Keep in mind that safety standards are always subject to interpretation, and that local authorities with jurisdiction may require prevention methods beyond those listed by the Occupational Safety and Health Administration, the International Fire Code or NFPA, or in this article

Common Causes of Fire in Liquid Applications

Flammable material, an oxidizer (such as air), and a spark or source of ignition are the three elements required to cause a fire or explosion, and these components can all be present in the liquid application environment.

• Liquid applications put millions of fine, flammable particles into the air. Different types of paints feature varying degrees of combustibility, but even waterborne paints contain small amounts of flammable chemicals.
• If a spray booth and its filtration system are not properly maintained, overspray can accumulate on the booth’s floor, walls and ductwork. Spray guns and equipment can also harbor enough paint particles to create issues.
• The use of spark-producing equipment (friction, cutting, welding or grinding in the spray area) can quickly create a source of ignition. 

Safety Best Practices

The points above provide a good starting point for eliminating dangers and maintaining a safe environment for your liquid application process. While the quality of the final finish is not the concern of those creating safety regulations, the velocities used in paint booths today exceed the minimum requirements for fire safety. To avoid safety issues while ensuring the best finishing environment possible, consider the following precautions:

Storage: Paint and hazardous liquids should be stored in what are called hazardous material storage buildings. Designed for indoor and outdoor use, these portable, fire-rated structures hold large amounts of liquid chemicals and waste, and feature explosion-relief wall panels, a weather- and chemical-resistant coating, extra-large spill containment capability, and a built-in ventilation system. 

Mixing: Industrial paint mix rooms provide a controlled area for safely mixing paint. Although only a limited amount of paint can be stored in such a mix room (depending on its proximity to the spray area), they feature containment bases for spills and airflow that allow chemicals and contaminants to be moved out of the enclosure while painters mix product.

Application: Liquid coatings should be applied in a spray booth that has sufficient airflow to move overspray away from the floor, walls and product being painted and into exhaust filters. Painters should always wear proper painting gear during application and use clean equipment. Particle control mats can be used to prevent static, and paint and prep should always be separated to prevent sparks and the mixing of contaminants. 

Cleanup and maintenance: Establish a regular schedule to change intake and exhaust filters. Clogged or overloaded filters will not allow proper airflow through the booth, which negatively affects the ability to clear the spray environment of contaminants. In severe instances, clogged filters may create flammable or explosive conditions within the booth.

As stated earlier, standards are subject to interpretation. Also, remember that the local authorities that have jurisdiction may require further prevention methods. How strict they are may depend on your past safety record. Your safety record will also impact your insurance costs.

Visit the websites of the International Code Council (iccsafe.org) and NFPA (nfpa.org) for more information and access to standards and codes. Finally, follow the safety information on the equipment you have purchased, train your personnel properly, and don’t let down your guard. 

Mark Freels is in territory and industrial sales with Global Finishing Solutions. Visit globalfinishing.com.