The share price of Growth Enterprise Market-listed Greencool Technology, a refrigerant distributor, plunged for a second day. The fall came despite a rebuttal by its chairman of accusations by a mainland magazine about the integrity of the company. The share price ended yesterday at HK$2.55, down 10.5 per cent from the previous day, when it lost 19.1 per cent. Doubts cast by Caijing on Greencool's claims about its products' uniqueness and energy-saving capabilities aroused fund managers' suspicions about other Hong Kong listed mainland private enterprises. The price of mainboard-listed corn-refiner and processor Global Bio-chem Technology tumbled 10 per cent to HK$2.45, while GEM-listed natural gas supplier Xinao Gas Holdings fell 6.1 per cent to HK$2.27. Greencool said it was collecting information regarding the magazine's claims and reserved the right to take legal action on the matter. In a teleconference with fund managers on Thursday, Greencool chairman Gu Chujun rejected the magazine's claims that some of Greencool's products were not endorsed by Ashrae (American Society of Heating, Refrigerating and Air-Conditioning Engineers). He admitted that one of the products, R405a under Ashrae coding, had not received approval from the United States Environmental Protection Agency. Greencool's listing prospectus said its refrigerants had been 'designated by Ashrae with the serial names of R405a, R411a, R411b and R411c'. It did not elaborate on what it meant by 'designate'. Engineering consultant James Calm, who sits on Ashrae's committee for awarding designation and safety classifications, said in an e-mail to Business Post last week: 'Ashrae does not accredit or approve refrigerants in China, in the US or elsewhere. 'Ashrae Standard 34 does provide standard designations and safety classifications following prescribed approaches through a consensus process, but some refrigerants are used commercially without [them].' Mr Calm said that, while R411a and R411b were approved, R411c's application had been pending since it was lodged several years ago. R405a was approved, but its safety clarification was later retracted as it contains materials that were deemed to contribute to global warming under Ashrae standards. He also said: 'I am not aware of any commercial use of R405a, R411a or R411b in the US.' Mr Gu told fund managers Greencool's products were recommended by Britain's Ministry of Trade and Industry and had been sold in Europe for 10 years. He also defended Greencool against claims by Caijing that Greencool had over-stated its energy-saving capabilities - which are 15 per cent to 25 per cent, according to the prospectus. He said it had bought product liability insurance under which customers would be compensated 300,000 yuan (about HK$281,100) if energy savings were proved to be less than 10 per cent, adding no claim had so far been lodged. Energy-saving is the company's key product feature, as Greencool does not charge its customers for refrigerants nor the labour on their replacement, and only 10 per cent of the electricity cost of the equipment for the first six to 10 months after replacement.