CHINA'S establishment of a quality assurance system for export products has opened up a potential market for Hong Kong companies which specialise in quality testing services. With the introduction of the quality assurance system, products made on the mainland would achieve better quality levels, and as a result people's perceptions of China-made products would improve, said an executive with a United States-based testing and inspection laboratory. ''This move reflects the Chinese Government's commitment to developing quality assurance and progress towards a mature economy,'' said Mark Hudson, managing director (Asia Region) of ACTS Testing Labs. ''Many mainland and Hong Kong factories which have moved to the mainland do not understand the importance of the safety standards of importing countries, so under some circumstances they will produce products that are sub-standard and might be banned from being sold in those countries,'' he said. With the introduction of the new quality control methods, more factories would receive information about product quality, thereby acquiring a better understanding of other countries' safety requirements which would, in turn, improve their own products, he said. ACTS would be able to assist manufacturers in safeguarding their export markets by helping them understand which product safety standards were suitable for them, then conducting tests on their products to make sure they adhered to the standards, Mr Hudson said.