Toxic chemicals are easily identified by the "Skull and Crossbones" pictogram under the globally harmonized system (GHS) of hazard communication. The symbol is easily recognized as a skull and crossbones.
The older-style toxic hazard symbol, which has now been phased-out, also depicts a skull and crossbones, but is instead contained within a bright orange square. Any in-house / custom labels should be replaced with new GHS-compliant labels.
The U.S. Department of Transportation (DOT) placard is used to label shipments of toxins during shipping.
Toxic Hazard Criteria
A substance will be considered to present a toxic hazard requiring the use of procedures for toxic chemicals when any one of the following criteria is met:
- The SDS or container label identifies or describes the substance as toxic.
- The substance meets the definition of toxic in the Hazard Communication Standard (29 CFR 1910.1200 Appendix A):
- The median lethal dose (LD50) is more than 50 mg/kg of body weight but not more than 500 mg/kg of body weight when administered orally to albino rats weighing between 200 and 300 grams each; or
- The median lethal dose is more than 200 mg/kg of body weight but not more than 1000 mg/kg of body weight when administered by continuous contact for 24 hours (or less if death occurs within 24 hours) with the bare skin of albino rabbits weighing between two and three kilograms each; or
- The median lethal concentration (LC50) in air is more than 200 ppm by volume of gas or vapor but not more than 2000 ppm by volume of gas or vapor, or more than two mg/L but not more than 20 mg/L of mist, fume, or dust, when administered by continuous inhalation for one hour (or less if death occurs within one hour) to albino rats weighing between 200 and 300 grams each.
- And substance whose toxic properties are unknown.