BEIJING (Reuters) - China will send out inspection teams to ensure that its provinces are complying with tough international restrictions on the production of ozone-depleting substances (ODS), government officials said on Monday.

China is a signatory of the 1987 Montreal Protocol, a global treaty that commits countries to phasing out the manufacturing of chemicals that not only contribute to global warming, but are also responsible for depleting the ozone layer, which protects the earth from harmful ultraviolet light.

The country has already eliminated 280,000 tonnes of annual ODS production capacity and has also pledged to speed up efforts to phase out hydrochlorofluorocarbons (HCFC), ozone-damaging refrigerant gases, as soon as possible, said Zhao Yingmin, the country’s vice environment minister, during a briefing.

But Chinese companies have been accused by environmental groups earlier this year of using a prohibited ozone-depleting chemical known as CFC-11, which serves as a blowing agent in the manufacture of polyurethane foam.

Zhao said China would “resolutely crack down” on any violations of the Montreal treaty.

China has a large number of foam manufacturers scattered throughout its regions and has struggled to bring them into line, with inspectors lacking the equipment and the resources to test for ozone-depleting chemicals.

Chen Liang, director general of the Foreign Economic Cooperation Office at the Ministry of Ecology and Environment, told Reuters that inspectors were now paying extra attention to violations and had a policy of “zero tolerance”.

He said inspections had already been completed at 1,700 of China’s 3,000 foam manufacturers, but only a few traces of CFC-11 had been discovered. Authorities are still running investigations to determine if they are truly illegal ODS.

“It will take time for China to eliminate all kinds of ODS,” he said.