NR 438 Specific Rule Information for Flour Dust

The term Flour Dust (PDF, 82KB) applies to the ground grain that is processed, stored, or handled. This includes all types of grain (e.g. wheat, rye, millet, barley, oats, or corn cereals, or a combination of these). This does not include soy flour. This definition is the same definition used by the ACGIH documentation of TLVs.

The size fraction used for emission calculations is PM₁₀.