Charleston, W.Va. ? West Virginia alerted its underground coal operations Thursday about potential problems with emergency air packs after decay was found inside packs carried by state mine inspectors.

The nine SR100 air packs randomly tested were not equipped with a heat damage indicator and may have been damaged while stored in hot vehicles, according to the state Office of Miners’ Health Safety and Training.

The state wants mine operators to immediately remove any air packs from service that do not have heat indicators.

As of Aug. 21, 63 air packs lacking heat damage indicators were still being used by mine inspectors. The state chose 17 of those at random for testing on a breathing simulator at Pleasant Prairie, Wis.-based Ocenco Inc., which is the only manufacturer of automated breathing simulators.

The aim is to learn more about equipment that has come under heavy scrutiny after deadly accidents this year.

A dozen miners were killed in a Jan. 2 explosion at the Sago Mine and two miners died in a belt line fire Jan. 19 in Logan County.