Fire Department Warns Hand Sanitizers May Explode In Hot Car, But Can It Really Happen?

The Western Lakes Fire District says the heat may cause an explosion; we did some fact-checking.

The Western Lakes Fire District (WLFD) based out of Oconomowoc, Wisconsin, has taken to Facebook to inform people of the dangers of leaving hand sanitizer in hot cars, but not without some controversy and accusations of misleading claims.

The fire department shared an image (seen above) showing part of a vehicle’s interior door panel smoking and melting. It warned that, as most hand sanitizers are alcohol-based, they could be extremely flammable.

“Keeping it in your car during hot weather, exposing it to sun causing magnification of light through the bottle, and particularly being next to open flame while smoking in vehicles or grilling while enjoying this weekend, can lead to disaster. Please respect the possibilities and be fire safe,” the department urged.

The posting also includes links for additional information from the National Fire Protection Association through a PDF file dated June 2010 and a safety video on YouTube uploaded in April this year.

What’s the problem?

Many social media users took issue with WLFD’s posting for a number of reasons starting with the image that the department used to show the dangers of leaving alcohol-based hand sanitizers in your vehicle. As reported by several news outlets afterwards, including WLNS, a fire official has since confirmed that it’s an older image that wasn’t taken in Wisconsin but instead originates from Brazil, allegedly after a bottle of hand sanitizer reportedly contacted an open flame.

Let’s start today with a little education!We’ve chatted in the past about clear water bottles being kept in your…

Posted by Western Lakes Fire District on Thursday, May 21, 2020

Responding to a commentator who asked what was the “determined cause in this photo? Pressurized container?” the department seemingly appeared to acknowledge that the picture was unrelated: “It’s a fire in a door panel. We frequently see the same issues and level of damage from smoking in vehicles.”

This brings us to the main issue with the department’s posting and in particular, that the public would assume that just leaving an alcohol-based hand sanitizer bottle under direct sunlight in the car could potentially lead to a fire.

The Western Lakes Fire District stands by its claim

One Facebook user pointed out that, “It’s not going to ignite unless exposed to an ignition source. The car temperature would have to get well over 300 degrees for it to combust on its own. So unless you’re putting an open flame to it, you don’t have to worry about fire.”

The department seemed to defend its warning in its response: “You are correct that the car temperature would not have to reach 300 F. However, the interior of the container would which is very possible due to focused light through clear plastic. This is the difference we are talking about.”

The National Fire Protection Association says something different

However, the National Fire Protection Association in the video that was linked by WLFD in the Facebook posting claimed otherwise when asked by a Youtube user, “Say my car is sitting in the hot sun in the summer, should I be worried if my hand sanitizer is in the glove box, can it spontaneously combust just from heat?”

The National Fire Protection Association’s response was: “The vapors generated at the flashpoint of hand sanitizer discussed in this video still require an ignition source (like a flame from a candle) to cause the vapors being released by the liquid to ignite. For it to spontaneously combust with no other, external ignition source other than self-heating alone, you’d have to reach over 700 degrees F!”

Should we be worried about self-combusting hand sanitizers?

The risk of hand sanitizer causing a fire or some kind of issue when left in a hot car appears to be near zero without an ignition source or extremely high temperatures exceeding 700 °F / 371 °C according to National Fire Protection Association or over 572 °F / 300 °C according to Brazilian fact-checkers Aos Fatos and Estadão Verifica. As reported by the Poynter, a “study by Arizona State University looking at cars parked in triple-digit summer heat found temperatures topped out around 160 F (71.11 C)”. That’s way below the level cited by experts.

Sales of hand sanitizer have spiked amidst the ongoing coronavirus pandemic. In addition, many people are making their own hand sanitizer with things such as aloe vera gel and isopropyl alcohol, often at a ratio of 30 per cent gel and 70 per cent alcohol.

Additional reporting by John Halas

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