Someone appears to be producing a banned ozone-depleting chemical, interfering with the recovery of Earth's damaged ozone layer, according to a newly published study led by scientists with the National Oceanic and Atmospheric Administration. The illicit emissions are believed to be coming from somewhere in eastern Asia, but nothing else is known about the offender. It's a scientific whodunit. The scientists say the atmospheric level of trichlorofluoromethane, or CFC-11, is ... not declining as quickly as it should be. "It appears that emissions of CFC-11 have increased in recent years, which is quite a surprise given the fact that production has been phased out," [the study's lead author Stephen] Montzka says. CFCs, or chlorofluorocarbons, "were once widely used in the manufacture of aerosol sprays, as blowing agents for foams and packing materials, as solvents, and as refrigerants." But scientists realized the chemicals were harming the ozone layer. So in the late 1980s, the world agreed to phase out the use of the chemicals. Production was supposed to have stopped as of 2010. The amount of CFC-11 in the atmosphere should be declining more and more each year, allowing the ozone layer to replenish. The scientists ... concluded that CFC-11 emissions started to increase after 2012, two years after production of the chemical was reportedly at zero.