It's not a widespread trend, but a number of incidents have been reported recently about vaping units, or e-cigs, exploding in people's mouths or hands. At least 4 such incidents have happened in Washington state alone.

According to officials with the American Vaping Association say the very small but troubling trend is the result of bad or defective batteries. They say it's no different than a few years ago when a string of exploding cellphone incidents had people on edge.

Several dozen reports nationally and worldwide were reported with various phone models that came apart or literally popped open due to batteries that overheated or malfunctioned. Experts say it has to do with the relatively recent introduction of powerful but tempermental lithium-ion batteries, which require proper care and maintenance. You can' just abuse them like older batteries.

However, in the case of the electronic cigarettes, the units have caused severe enough injuries that at least four people have been treated at Harborview Medical Center in Seattle for what were called gruesome injuries involving burns and other disfiguring issues.

24-year-old Daniel Pickett of Cashmere, WA is one of the Washington state victims. According to his attorney, who plans to represent him in a lawsuit over the issue, Pickett said his e-cig began to make a funny sound, then a second later it literally exploded, making "a mess" out of his hand and arm. Fortunately,  it was not in his mouth at the time. He's undergone five surgeries, but still doesn't know if he will regain use of his right hand.

Since 2009, there have been at least 25 documented cases of exploding e-cigs, but the number has ticked upward considerably in the last couple of years. This is troubling for the $2.2 billion dollar industry.  E-cigs, or vaping as it's known, has been heavily pushed as a safer alternative to tobacco-smoke products.

Officials say like cellphones, e-cigs pose no significant risks if used or charged properly. However, American Vaping Association officials say too many people are charging them improperly, or using units that have defective or damaged batteries. Also, using the units under extreme weather weather conditions (such as a pouring rainstorm or snow) can cause electrical shorts, leading to issues.

The federal government doesn't track accident reports related to vaping, mainly because it's such a new industry. But some safety advocates are pushing them to do it.

So, the message is for vapers, follow the instructions, take care of the unit, and if you suspect ANY issues, make sure you consult with the manufacturer or vendor about whether the unit is safe for use.