How to Test for Combustible Dust: BAM Fallhammer Drop Impact Test

 Any new material being produced or any existing material with a process change should have screening tests performed to ensure that they can be safely handled and classified for transport. The Go/NO-GO screening test (per ASTM E-1226) and the BAM Fallhammer are two such screening tests.

While some powders are deliberately manufactured to possess highly energetic behavior (think TNT), other materials often have explosive properties if they are processed small enough and if an ignition source is present. In fact, most organic materials (from plastics to metals to coffee creamer to corn starch) are explosive if they have a small enough particle size and if there is enough material present. This post explores why screening tests, specifically the BAM Fallhammer are an essential tool for guiding the safe handling organic materials.

1. What is the BAM Fallhammer Test?

The BAM Fallhammer test is used to determine the sensitivity of a given solid (including pastes and gels) or liquids to impact forces by allowing standard hammer weights to fall on a confined quantity of sample and measuring the fall height required to decompose, or detonate, the charge.

In plain English, the BAM Fallhammer measures the sensitivity of a material to mechanical forces. This test basically shows what happens if a box of the material falls during shipping or if it is struck while in storage (by a forklift). The test also provides invaluable information for safer material handling and processing in industrial plants. This information is essential for plant managers and safety personnel.

2. Who Determines how to handle a sample Safely?

The BAM Fallhammer test apparatus complies with the UN Transport of Dangerous Goods Manual of Tests and Criteria and also to the Classification, Packaging and Labeling of Dangerous Substances in the EU Part 2- testing methods (latest editions). The test method used in both standards yields quantitative results in the form of a limiting impact energy. These results are used to determine whether a substance can be transported in the same form as it was tested and also provides the data for determining correct packaging symbol, danger indications and risk phrases associated with new and existing products.

This video demonstrates one BAM Fallhammer test conducted at Fauske & Associates, LLC resulting in a "good" ignition. When applying these results to process safety in industrial plants the impact energy -- typically given in Joules (1 Joule ~ ¼ calorie) -- can then be compared to theoretical values that may be present in various process scenarios. For example impacts from slide gates, bucket conveying equipment, or mixing paddles can all be potential impact scenarios that one can estimate contact energy levels.

For more information and help, visit www.fauske.com or call 1-887-FAUSKE1 (328-7531).