GENEVA - Countries at the World Trade Organisation complained on Friday about China's proposed Internet filter rules which the United States deemed draconian and the European Union urged it to scrap.

At a meeting of the Technical Barriers to Trade committee, which assesses unfair hurdles for exporters, WTO members also took aim at Canada's anti-allergy food labelling and the European Union's treatment of imported chemicals.

The complaints, if unresolved, could eventually escalate into formal disputes. When trade rules are breached, the WTO's court permits governments to impose hefty retaliatory sanctions.

Friday's talks centered on Beijing's requirement all personal computers be pre-installed by July 1 with Green Dam software that filters out objectionable material like pornography, which U.S. officials have said could be used for broader censorship.

The European Union strongly urged China to drop the rule, and Washington's representative called it draconian and said it could infringe on the intellectual property rights of U.S. companies, according to diplomats at the closed-door talks.

Japan also voiced concern about the measure, which China's delegate said was aimed at protecting minors from online pornography and was requested by parents and teachers.

Acer is the only personal computer maker that has said it would comply with the Chinese filter rules. Other major brands such as HP and Dell have said they would seek additional information on the matter.

China remained in the WTO hotseat for other issues.

The United States and European Union complained about a new Chinese standard for connecting mobile phones to the Internet, which strays from international standards.

South Korea said it was concerned about anti-bacterial and cleaning requirements for air conditioners, refrigerators, washing machines and dehumidifiers imported into China.

Thailand, China, Japan, Canada, the United States and Latin American members led by Argentina said their companies were facing great difficulties and high cost complying with the European Union's regulations on imported chemicals.

An EU directive on hazardous substances in electrical and electronic equipment and its ban on the use of nickle-cadmium in batteries were also targeted in the talks.

Brussels, in turn, said Canada's labelling requirements for ingredients that may cause allergies was not in line with international practice.

Canada said there was need for clear and understandable labels so that consumers might be aware of allergy-causing food, a trade official said.

Standards affecting imports of organic food to South Korea, medical devices to Brazil and car tyres to India were also in the spotlight.