How do I assign HMIS® numerical ratings (health, flammability, physical hazard) to a product?
HMIS® ratings are developed by comparing information on the health hazard, flammability, and physical hazard of the product to a set of criteria for each hazard category. The criteria indicate which numerical rating (0-4) in each category is appropriate for the material. Basing ratings on the inherent properties of the material helps keep ratings more consistent from company to company. However, there are times when it is appropriate to use professional judgement in creating a final rating value. If the product is a mixture of chemicals, the mixture is evaluated in the same manner as it is during MSDS development. In developing a product s rating, an employer must consider all ingredients present in concentrations of 1 percent or greater (0.1% if the ingredient is a carcinogen). The hazard rating for the product as a whole will reflect the ingredient with the highest rating, unless there is evidence that the rating should be different. Testing of the mixture as a whole could provide su
