Have you ever been to a propane station and seen this:
Well that is there for a reason, and it is all a result of an OSHA (Occupational Safety and Health Administration) standard called Hazard Communication. The short version of the Hazard Communication OSHA standard is that any company engaging in the manufacture of any type chemical is required to provide detailed information of the possible dangers to the end user, and to employees working with the chemical. The standard requires that the company producing the chemical have a program in place that includes a written safety program, safety data information for each product, proper labeling, and training.
Now, since we do not work at the facility that provides propane, we are not required to know all of this stuff, but it is good to at least know how to read the placards we see at propane stations, and on tankers driving down the road. Once you know how to read this placard then when you see these placards on big trucks you will immediately know the hazards of the cargo. This may be useful if you witness an accident involving a big truck in case you need to protect yourself or call into 911 with the proper information. These placards are an easy indicator for emergency personnel to identify what they are dealing with as they approach an accident involving chemicals.
So, this is all there is to it, the placard has colors that represent a particular hazard, and the number in the color represents the level of the hazard.
Blue = Health
Red = Flammability
Yellow = Reactivity/instability
White = Special Conditions
The ratings are from 0-4, with 4 being the highest level of hazard. So, if the red section has the number 4 in it, you know that this substance is highly flammable. If the red section has a zero in it then this substance does not burn. At a quick glance, you should be able to tell if a substance is dangerous to breathe or get on your skin by the number rating in the blue section (Blue=Health). The yellow section will give you a good indication of how volatile the substance is, for example, a rating of 4 in the yellow section could mean this substance can easily detonate! As for the white section, there may or may not be something listed in this section. If there is something in the white section it will be a symbol, not a number, for example, you may see a radioactive symbol. Here is a chart to help you along:
As RVers we see these placards frequently. I think it is a good idea to at least be familiar with what it means.