Surviving a Hazmat: The Rule of Thumb and the 3 U’s

Imagine this … you’re sitting there in your car waiting for the light to turn green and over to your left you see a huge flash of fire and then a split second later a deafening BOOM!

You’re in the middle of a train derailment, one where several rail tankers have collided and caused an explosion. Now there’s string of railcars and tankers, each carrying hazardous materials, on fire and releasing toxic vapor clouds into the atmosphere.

A fiery ball of black smoke billows hundreds of feet into the air.

Thick acrid smoke covers the entire downtown and travels several miles. Burning oil and chemicals rush through storm drains and sewers.

Lights and sirens. Your heart is pounding against your chest. Adrenaline is running through your veins . And, all you hear is a single thought … “This stuff is bad …explosion … fire ... I can’t breathe … What I am supposed to do? Where am I supposed to go? Am I going to die in this? HELP!!”


Quick thinking leads to increased survival rates. Remember “The Rule of Thumb” and “The 3 U’s “ — Up Stream, Up Wind, and Up Hill.

When I initially started my training in hazardous materials, there was always a reference to this “Rule of Thumb.” It was frequently discussed as a good ol’ strategy for responding to an unknown hazardous materials incident. Although the “Rule of Thumb” is generally defined as a procedure or rule based on experience and practice, first responders have all used it to size up an unknown hazard.

By extending your arm and holding your thumb out, close one eye. If you can cover your view of the incident with your thumb, then you are generally far enough away from the bad stuff. This approach emphasizes on the defensive strategy during the incidents. This is a simple, and easy, defensive move you can benefit from. Getting you and your loved ones to safety is your priority. Use the “Rule of Thumb” to get to that safe location.

So imagine this again, you’re sitting in your car waiting for the light to turn green. Explosion, fire, BOOM. STOP. Think and remember the “Rule of Thumb” and “The 3 U’s.”

If you’re able to, roll up your windows and quickly turn your AC on to recirculate air flow. This prevents fresh air, and any potential contaminants, from coming in through your vents.

Look around you. Which way is the wind blowing? Do you see tree branches, leaves, flags swaying in a direction. If so, drive in the opposite direction. Go upwind and away from the release. Drive or run quickly away using “The 3 U’s” to get safely away from the explosion or any hazardous material release.

In most cases, going uphill or to higher elevation will prevent the runoff from coming towards you. And, of course, if you’re near a waterway, always go upstream from the release. Get as far as you can safely from the incident. You can use your thumb to guide you. Those first few minutes are critical and it’s on you. Listen for any sheltering in place alerts or evacuations from first responders.

Remember — “Rule of Thumb” and “The 3 U’s.”

Survive. Be Prepared. Plan.

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