NFPA Dust Testing

NFPA Dust Test Deadline Approaching, September 2020

If your facility produces dust National Fire Prevention Association (NFPA) Standard 652 requires that you have to have a dust test and dust hazard analysis (DHA) completed by September 2020. Nauset Engineering is here to help your company complete both the dust test and the DHA. 

NFPA Standard 652 covers the Fundamentals of Combustible Dust, and Combustible dust fans are designed to meet NFPA requirements. If you know your dust isn’t combustible, you still need to provide documentation showing that it’s not. For example, there’s lots of documentation that silica dust isn’t combustible. If not, you need a dust test.

How does a dust test work?

When you send your dust off to a testing company, what do they do with it? Let us explain:

The first dust test is typically the “go/no go” test. The “go/no go” test determines the explosiveness of the dust. The result of “go” means that under basic testing, the dust will explode. The result of  “no-go” means the dust is non-explosive, but the dust is still possibly flammable.

What’s the difference between flammable and explosive? An explosion, by definition, moves faster than the speed of sound. Explosive dust can generate a pressure wave able to move that fast. Flammable dust may create a fast-moving flame front, but it lacks the pressure or speed of an explosion.

how dust tests work

The industry uses is the Know Sure Thing (KST) as a standard measurement of dust’s explosiveness. A dust with KST below 100 is considered a minor explosion. Below 200, the explosion is considered strong, and above 200, the explosion will be very strong.

This information can help prevent a lot of problems. LIT, for example, tells you how hot a surface (like an overheating bearing) can get before it will ignite a layer of dust. MIE (this is a measurement of temperature) tells how dust will respond to a spark or other ignition source. At a very high MIE, the dust won’t ignite without a lot of energy input. At a very low MIE, dust will ignite from even a tiny spark or even something as small as a static charge.

What comes after the dust test?

After your dust test shows that your dust is combustible, you will need to complete a dust hazard analysis (DHA). NFPA 652 does not specify who should do this, as long as they are “an expert” and their knowledge is satisfactory to the facility owners. Safety, maintenance, and shop floor managers can all be involved.

Nauset Engineering is here to help

If you have concerns that your industrial dust collection system may not meet safety standards, contact Nauset Engineering and a service technician can help evaluate your system’s performance.


How to submit dust for the NFPA 652 dust test

Take samples from the dirty air side of the dust collector for best results. For an accurate measurement, empty the collection drum and then collect a recently pulsed sample. In a full drum, large particles may settle and leave smaller ones at the top.

If you don’t have a dust collector, you can collect dust from surfaces or machines in your shop. Just make sure the sample represents your general dust. Don’t collect damp dust or large chunks.

Ship your sample in a well-sealed container. Include an MSDS sheet and follow all MSDS transport precautions for that material.

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