NFPA Hazard Rating System

NFPA Hazard Rating System from Northeastern University

NFPA Hazard Rating System

Northeastern University's laboratory doors are posted with emergency information to warn occupants
and The Boston Fire Department personnel of the presence and identification of hazardous materials inside each laboratory. The National Fire Protection Association (NFPA) has developed a system for
indicating the health, flammability, reactivity and special hazards for many common chemicals through use of the NFPA 704 Diamond. The hazard rating for the laboratory is determined by looking at all the chemicals, gases and special lab uses in the laboratory and coming up with a rating for each hazard category based on criteria established below.

Please read the rating information in each category, take an inventory of your laboratory and rate each category accordingly. To look up a rating for a particular chemical click on the link at the bottom
of the page. If you do not find the chemical listed, a review of the chemicals MSDS sheet may help you rate the chemical in question. To look up a chemicals MSDS click on the "MSDS" link at the bottom of the page.

If there are any questions regarding a chemical rating, please either email your question or call the Office of Environmental Health and Safety at x2769.

If you have a new laboratory or are a new Principal Investigator, please contact EHS:

Rating Summary


Use the most severe rating code regardless of volume.

Health (Blue) Detailed Description of Health Rating

4 Danger May be fatal on short exposure. Specialized protective equipment
3 Warning Corrosive or toxic. Avoid skin contact or inhalation
2 Warning May be harmful if inhaled or absorbed
1 Caution May be irritating

No unusual hazard


The greatest volume of one code determines the marking. The only exception is if a more severe code has a volume of 3 gallons or greater, then that code is used instead of a lower code of greater volume. If the laboratory total volume of flammables or combustibles is less than one pint for all, then the rating for the laboratory for this area shall be zero

Flammability (Red)Detailed
Description of Flammable Rating

4 Danger Flammable gas or extremely flammable liquid
3 Warning Flammable liquid flash point below 100°F
2 Caution Combustible liquid flash point of 100° to 200°F

Combustible if heated

Not combustible


Use the most severe rating code regardless of volume.

Reactivity (Yellow) Detailed
Description of Reactivity Rating

4 Danger Explosive material at room temperature
3 Danger May be explosive if shocked, heated under confinement or mixed
with water
2 Warning Unstable or may react violently if mixed with water
1 Caution May react if heated or mixed with water but not violently
0 Stable Not reactive when mixed with water

Special Information

Indicate the presence of the following regardless
of volume

Special Information Key
Detailed Description of Special Information Rating

Oxy Oxidizing Agent
W Water Reactive
G Compressed Gas
LN2 Liquid Nitrogen
LHE Liquid Helium

Special Signage Key (These are signs that
shall or must be posted in addition to the NFPA diamond)

LAS Laser
BL Biosafety Level
RAD Radioactive Material
X-Ray X-Ray Diffractometer
MAG Magnetic Fields
HVO High Voltage
NFPA Hazard Rating A - C
NFPA Hazard Rating D - I
NFPA Hazard Rating J - R
NFPA Hazard Rating S - Z
NFPA Rating Gases
NFPA Rating Rating - Text Version
Material Safety Data Sheets


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