Warning Signs

No, not the "When the sun rises with three red circles around it" type of signs, but the "Warning: the contents of this box can melt your face" type.

Since lawyers and bureaucrats like to stay in business, we have warning signs on just about everything (except lawyers and bureaucrats). Anyone old enough to read the warning label should know that you don't stick your hands under the deck of a running lawnmower or use a hair drier while in a bathtub full of water. Common sense and a little life experience will save you from being a candidate for next year's Darwin Awards.

Any sign that uses the term "Authorized Personnel" is just someone telling you that they don't want you to see what they have behind that door. It's usually just a cleaner bathroom than they present to the public.

There are some things that do need warning labels, though. A train derailing in your neighborhood or a fire at a nearby warehouse can be cause for immediate evacuation, and the clean-up could take weeks. Knowing what to look for is usually the first step in being aware of your surroundings.

Radiation

All radioactive sources must (by law) be labeled, since radiation is colorless, odorless, and can do damage from a distance. Because it is illegal to ship radioactive materials by airplane, they all travel on the same roads you use. Without good monitoring equipment, this is the premier "Keep Out!" sign.

Signs similar to this, but designating X-ray or radio frequency radiation, are there to keep you from wandering into an area that could have harmful radiations that are not produced by radioactive decay. Once the power is shut off these forms of radiation are no longer present, unlike the Alpha, Beta, and Gamma radiations produced by radioactive decay. If I ever get around to writing the "Physics & Chemistry for Preppers" series of posts, I'll describe radiation and radioactive decay is more detail.

In recent years, there have been a few thefts of old medical equipment that still contained lethal amounts of radioactive materials (old cancer treatment machines). Once the thieves figured out that they had messed up, they abandoned the machines in remote/rural areas. How'd you like to find that on your weekend hike?

Poisons and Dangerous Chemicals

There are commercial grade poisons out there, and I don't really care to be near them unless I'm in charge of them. Driving down the road next to a semi full of material that could kill everyone that comes in contact with it is more common than most people think. Rail cars full of chemicals roll through towns large and small every day; trucks break down and rail cars come off the rails sometimes; and warehouses catch fire and the smoke and fume can travel a long way.

Luckily for us, the National Fire Protection Association (NFPA), the same folks who give us safer electricity through the National Electrical Code (NFPA 70), has set standards for labeling dangerous chemicals in containers. If you see the familiar diamond with four differently colored segments, that's an NFPA 704 sign. The numbers represent the level of danger (0=minimal hazard, 4=extreme hazard) and the four colors are to identify the hazard in different classes

• Red = Flammability. How likely is it to catch fire?
• Blue = Health risk. How likely is it to cause injury?
• Yellow = Stability. How likely is it to have violent chemical changes or explode?
• White = Special hazard. Does it need to be kept away from water? Is it an Oxidizer? Is it corrosive?

http://www.compliancesigns.com/NFPA-Chart_1.shtml

Other Physical or Chemical Hazards

There are a lot of things out there that can cause damage by exploding, burning, freezing, asphyxiating, etc. The Department of Transportation (DOT) has rules in place for placing "placards" on vehicles carrying these kind of hazards. Like the NFPA 704, DOT placards are diamond-shaped, but the color of placard designates the hazard and other information will be on the placard. Basically, red is for flammables (diesel fuel, gasoline), green is for non-flammable compressed gasses (anhydrous ammonia or nitrogen), orange is for explosives (with the numbers indicating class of explosive), and so on. Learning the proper use of placards is about a four-hour class, since they cover such a large variety of hazards. If you're really interested, ask at your local community college or truck driver training company. 

https://classes.hazmatschool.com/images/5-Traincrd10back.jpg

A handy guide to hazardous material shipping is the Emergency Response Guide. It has lists of the most common hazardous materials and the placard information for each of them. There are also Android, Apple, and Windows apps available with the same information. It's a quick way to tell what's on that truck that just went by you at 90mph so you can decide how far away from him you need to stay.


Paying attention to what is around you (AKA situational awareness) is only of use if you can identify the hazards. Not knowing the difference between a container of water and a container of poison will cause either a lot of needless panic or a lot of needless injury.