‘Flame jetting’ is dangerous phenomenon — and can ruin your Fourth

Even if you are following all safety precautions regarding the operation of at-home fireworks, state fire officials are warning of external factors that could cause your Fourth of July celebration to go up in flames.

The New Jersey Division of Fire Safety wants to make residents aware of something called "flame jetting." That happens when a container of flammable liquid with a long neck is poured out near a flame source, and the vapors built up inside the neck ignite in a streak of fire that can reach 10 to 12 feet long.

According to Richard Mikutsky, NJDFS director and state fire marshal, conditions need to be just right for a flame jet to occur, but the results can be catastrophic.

"The container needs airspace above the fuel, and what happens is the fuel evaporates into the airspace, and then it makes a mix of the fuel and oxygen," Mikutsky said. "The forces that are within the container come out under pressure as millions of tiny little droplets, basically a mist."

The shape of a container matters, Mikutsky said. Those with wide openings provide less of an opportunity for vapor buildup.

As for liquors with high alcohol content (around 150 proof), many of them already come with "flame arrestor" caps which allow for vapors to escape a bottle, but if they don't, NJDFS guidance says those cost only about 50 cents each.

"Flame arrestors are very effective in preventing these flame jets. One thing they do is they limit the rate of the oxygen" that enters a container, Mikutsky said. Under those conditions, anything that ignites quickly becomes starved of oxygen and is extinguished.

Mikutsky said the best advice is to be conscious of what you are bringing to your outdoor cookout or fireworks display.

"Just common sense, make sure that you keep clearance, make sure there's no heat source or flame nearby," he said. "We want everyone to have a happy and healthy holiday."

Patrick Lavery is New Jersey 101.5's afternoon news anchor. Follow him on Twitter @plavery1015 or email patrick.lavery@townsquaremedia.com.