The red plastic portable gasoline containers consumers use to fill lawnmowers, snow throwers, and other equipment pose an explosion hazard under certain conditions.
Lab tests indicate that under certain rare conditions, gas vapor mixtures can explode inside those cans and cause significant injuries, an NBC News investigation reports. The federal Consumer Product Safety Commission (CPSC), at the request of NBC News, analyzed incident and injury databases and counted at least 11 reported deaths and 1,200 emergency room visits involving gas can explosions during the pouring of gasoline since 1998.
When there is a very little gasoline left in the container, NBC News explains, a flashback explosion can occur when escaping gas vapor comes in contact with an ignition source – a flame or spark. The vapor outside the container can ignite and “flash back” inside the can. If it does, and if the gas/air vapor mixture inside the can is a certain concentration, that mixture can ignite and cause an explosion of flame.
NBC News reports that over the last two decade at least 80 lawsuits have been filed by ndividuals injured in alleged gas can explosions. The suits have argued that portable plastic gas cans are dangerous and “unsafe” because they are “susceptible” to flashback explosions. Blitz USA, until recently the largest manufacturer of plastic gas cans, and Wal-Mart, the largest seller of the cans, have been named as defendants in most of the suits.
Scientists at Worcester Polytechnic Institute’s combustion lab conducted tests on the gas cans with the support of the gas can industry, and concluded that “flashback” explosions inside the cans are possible under certain conditions. Tests conducted for plaintiffs’ attorneys, for a government criminal investigation, and for NBC News all reached the same finding.
Blitz and other manufacturers have argued that user injuries were caused by the users’ negligence or misuse of the gas cans, and that the cans were not at fault. But the industry is studying the feasibility of adding flame arresters of the type used in metal “safety” gas cans and storage containers of other flammable liquids.