The US Department of Transportation requires shippers and carriers to label vehicles that are carrying hazardous materials. This has to be accurate because in the event the vehicle is involved in an accident, first responders need to know how to approach the situation and if any specialized safety equipment is needed. One of the easiest ways to identify the information on these placards is through the colors and patterns used. Here is a brief guide to HAZMAT placard colors so you can identify what these trailers contain without needing to read them:
Orange – Represents packaged explosive materials including dynamite, fireworks, and ammunition. The type of explosive is noted on the placard but orange always identifies products that can be explosive under certain conditions.
Red – Represents flammable products like gasoline, fuel oil, acetylene, rubbing alcohol, paint, and acetone. They also feature a flame image and a notation of what the flammable materials are.
Green – Represents non flammable gases like argon, usually used in welding. Tye green denotes no fire risk, but the contents may be under pressure which is a hazard for first responders.
Yellow – Represents oxidizers which are substances that when mixed with oxygen are likely to combust like ammonium nitrate, potassium nitrate, and halogens.
White – Represents poisonous and biohazardous substances like dyes, acids, aerosols and even medical waste. Toxic materials will be labelled poison and have a skull and crossbones symbol.
Blue – Represents goods that are dangerous when wet and includes substances like sodium, calcium, and potassium.
Red and White – These placards represent very dangerous substances that may ignite when exposed to air including white phosphorus and aluminum alkyls.
Red and White Stripes – Represents flammable solids that can easily combust such as matches and magnesium.
Red and Yellow – Represent organic peroxides which can ignite and explode such as benzoyl peroxide.
Yellow and White – Represents radioactive substances that are commonly found in medical equipment. These placards will contain the radioactive symbol.
White and Black – Represents corrosive materials that can harm the skin including batteries, hydrochloric acid, sulfuric acid, and sodium hydroxide.
White and Black Stripes – Represents hazardous substances not categorized by the above such as dry ice, and asbestos.