Keeping your paintbooth OSHA compliant
A paint booth is more like a room that is enclosed specifically for contaminant-free painting of various things. Paint booth ventilation design is important to create a safe environment for painting and to meet OSHA requirements. To protect the general population environment and the person inside the paint booth, OSHA had created requirements for paint booth fans and filters to assure that paint booth ventilation is safe.
There are two types of high-efficiency filters for paint booth ventilation. One is a paint booth exhaust fan installation that captures over-spray before it enters the general environment. The other filter is an intake filter that catches dirt, dust, insects, and other contaminants before they enter the paint booth.
What is a downdraft spray booth?
A downdraft paint booth ventilation delivers clean air down from the ceiling from the roof and exhausts on the floor. The purpose of this downdraft is to create clean air to enter the paint booth, making it a healthy and safe environment for the person painting. It also ensures a clean air quality for a flawless finish, free of debris, dirt, and dust.
How does a downdraft paint booth work?
The overspray is exhausted with the downdraft paint booth ventilation regardless of where the painter is spraying and keeps the airflow from crossing over the painter or the item being painted so that it is exhausted. The process pulls the overspray down and away instantly and ensures that the overspray doesn’t cover the painter or the freshly painted item.
Why do spray booths operate at negative pressure?
Paint booth ventilation function at negative pressure to prevent the fine mist from airborne paint entering the general workplace. The air pressure is slightly lower than the surroundings, which draws air into the paint booth.
What does positive air pressure mean?
Regarding paint booth ventilation, positive air pressure is increasing the filtered air inside the cleanroom than what is surrounding space of the cleanroom. There are various falling levels of positive air pressure from the cleanest room with the highest pressure to the airlock room.
How do you measure airflow in a paint booth?
There are two basic methods for testing a paint spray booth operation:
- Airflow testing.
- Worker exposure to spray paint discharges testing.
Face Velocity Testing Air Flow
There must be enough airflow in the paint booth to overcome any overspray out of the spray gun. Testing the paint booth ventilation’s face velocity, a velometer is used along with a thermo anemometer and vane anemometer at the spray paint booth face, using a simulated grid on the paint booth’s face.
Capture Velocity Testing Air Flow
Capture velocity is the true air movement measurement effective in holding the paint spray. This is where the airflow is emitted at the breathing zone of the operator.
Worker Exposure Testing for Booth Air Flow Effectiveness
The true measurement of the airflow’s effectiveness whether the protection for the operator is protecting him/her from the paint spray particulates and solvents. If the exposure to the operator is within acceptable terms, OSHA Compliant or other limits, they deem the spray booth to be in proper performance.
What Are OSHA’s Requirements for Paint Booth Ventilation?
The OSHA criteria for design and construction of spray paint booths and ventilations are many wide-ranging, can confuse and be overwhelming. The following is an abbreviated version of OSHA requirements. The best way to make sure your paint booth ventilation is up to OSHA requirement is to hire the services of an authorized paint booth contractor.
- Construction of paint spray booths shall be significantly constructed of steel that is rigidly and securely supported, and not of any noncombustible material such as aluminum. They are to be designed to where air currents sweep in the direction of the exhaust outlet.
- Spray paint booth interior surfaces are to be continuously smooth with no edges and designed to avert residue pocketing and enable cleaning and washing without harm.
- The surface of the spray paint booth and working area for the paint operator need noncombustible covering that will enable residue removal and safe cleaning.
- Baffle plates shall promote the air in an even flow through the booth or initiate an overspray deposit before entering the exhaust duct, are to be made of noncombustible material that is easily accessible or removable for cleaning both sides. The plates are not in the exhaust ducts.
- For dry type overspray collectors aka exhaust air filters in standard dry type spray paint booths, installed filter rolls or overspray dry filters are to conform as follows:
- Except for electrostatic spraying operations, the spraying operations shall be designed and installed and standard maintenance so that the normal air velocity over the booth’s open face or cross-section in spraying operation, shall no less than 100 lfpm. An air velocity over a spray paint booth open face is not less than 60 lfpm or more dependent on the amount of the finishing material being utilized and its explosion and flammability characteristics.
Again, refer to a qualified contractor that is knowledgeable of OSHA requirements as well as any local laws. You can also refer to OSHA.gov website for detailed information. If necessary, consult with organizations like Contractor Society Of America to ensure your contractor is qualified. Need ventilation for your paint booth in Mansfield and Arlington, TX? Call C&S Air, Inc. at (817) 398-8887 today!