The National Fire Protection Association (NFPA) is the group behind the well-known labeling system that uses colored diamonds to alert people to potential hazards. They are commonly seen on shipping trucks and other areas where hazardous materials are present. Part of this labeling system is the numerical rating system that alerts people to the severity of the risk that is present in a given area. Understanding what these ratings mean is essential for ensuring the proper precautions are taken in a given situation. The ratings are broken up into three categories, and are assigned a number between zero and four, with four being the most severe.
Health Hazard Ratings
The health hazards category, which is represented in blue on labels, is for any materials that can cause problems with your health if exposed. The ratings are as follows:
- 0 – Normal material that has no health hazard associated with it.
- 1 – Material that is ‘slightly hazardous’ to your health.
- 2 – Hazardous materials. Anyone working with this type of material should use protective equipment.
- 3 – Extremely dangerous materials requiring protective equipment and strict safety standards.
- 4 – Deadly materials. Every precaution must be taken when handling or working with this material.
Fire Hazard Ratings
The fire hazards category, which is represented in red, is for any materials that can ignite and cause injury. The ratings are based on the flash point of the material and are as follows:
- 0 – The material will not burn
- 1 – The material has a flash point of above 200 degrees.
- 2 – The material has a flash point below 200 degrees.
- 3 – The material has a flash point below 100 degrees.
- 4 – The material has a flash point below 73 degrees.
Instability Hazard Ratings
The instability hazards category, which is represented in yellow, is for materials that react in a dangerous way in various situations. The rating levels are as follows for this category:
- 0 – The material is stable.
- 1 – The material can become unstable if it is heated.
- 2 – The material can have a violent chemical change.
- 3 – The material may detonate if shocked or heated.
- 4 – The material may detonate unexpectedly.
Understanding the hazard ratings will help ensure you know how to prepare for working with potentially dangerous materials, and how to react should an accident occur. These ratings are intentionally simple to understand so people can recognize them at a glance and take proper precautions.