Another way to assess a chemical's safety properties without reading the MSDS is to look at the "hazard diamond" that is usually located on the label of the chemical.

Below is an example of a hazard diamond. Each of the colored boxes normally has a number from 0 to 4 in it that corresponds to the severity of that hazard (0 is no hazard; 4 is severe hazard).

hazard diamond with no numbers or symbols

Reactivity - YELLOW
0 = Normally stable
1 = Unstable if heated - use normal precautions
2 = Violent chemical change possible - use hose streams from a distance
3 = Strong shock or heat may detonate - use monitors from behind
explosive barriers
4 = May detonate- vacate areas if materials are exposed to fire

Fire Hazard - RED
0 = Will not burn
1 = Must be preheated to burn
2 = Ignites when moderately heated
3 = Ignites at normal temperatures
4 = Extremely Flammable

Health Hazard - BLUE
0 = Like ordinary material
1 = Slightly hazardous
2 = Hazardous - Use breathing apparatus
3 = Extremely dangerous - use full protective clothing
4 = Too dangerous to enter vapor or liquid

Specific Hazards - WHITE

Depending on the specific hazard posed by the chemical, you may see symbols like the ones shown below within the WHITE area of the hazard diamond:

biohazard symbol
Biohazard

  

flammable symbol
Flammable

  

poison symbol
Poison

  

do not add water symbol
Do Not Add Water
             

corrosive symbol
Corrosive

  

strong oxidizer symbol
Strong Oxidizer

  

radioactive symbol
Radioactive