'The major heat generating part is affected by moist conditions,' she said. 'In wet weather, or when using it with wet hands, there may be a danger of electrocution.' Both the massage machines had only two-pin plugs, meaning there was no provision for earthing.

Ms Ho said lack of double insulation and insufficient electric strength could also inflict an electric shock on the user.

She advised people who owned the machines to stop using them.

The council could not stop the sale of the machines and it was up to consumers to be aware of such issues.

'Currently there is no legislation prohibiting the sale of dangerous products,' she said. 'Consumers should always exercise care to choose among the wide array of massagers available on the market to avoid those which do not comply with safety standards.' A new government regulation which comes into effect in March will require all electrical appliances to carry three-pin plugs with proper earthing facilities, which means sale of the massage machines will be prohibited.

'Hopefully by then those products will have disappeared from the market,' Ms Ho said.

The senior researcher with the Consumer Council, Connie Lau Yin-hing, said the agents responsible for selling the machines had been notified, but had not responded to warnings.

'We contacted two agents. One of them did not respond and the other gave us a verbal agreement to stop selling but we have since found that they are still selling them,' she said.

Ms Lau said the Consumer Council was powerless to ban the sale of the products and could only wait until the new regulations came into force.

Ms Ho also warned people to be wary of sales tactics of people selling health and fitness equipment.

'Since 1992 the council has received 23 complaints concerning the sales practice of some vendors of health equipment including massagers and similar gadgets,' she said.

She said unscrupulous dealers would approach companies offering free talks on health education but their actual purpose was to sell health equipment, often at prices well above the retail norm.

Council research also found that impeller-type washing machines were more reliable than drum-type washing machines, with a breakdown rate of 13.3 per cent compared with 27.7 per cent.

The maintenance fee is higher for the drum-type, ranging from $280 to $700 compared with $200 to $350 for the impeller-type.

A particular brand of yellow chalk was found to contain excessive levels of toxic heavy metals such as lead and chromium, prompting the importer of Youth Colour - Chalks of Tiny Dust Art No 162 - to withdraw the product.