The Hong Kong Toilet Association says the government should increase its ratio of women's toilets to men's and include urinals in its calculation.

Henry Hung, the association's chairman, told RTHK that at the moment, there were two female public lavatories for every male one, but women could often be seen lining up outside the public facilities.

He said the government should increase the ratio to 1:2.5 and include men's urinals in the calculation of toilets.

Hung was speaking in an interview with RTHK's Hong Kong Today programme on Wednesday, to announce the results of its annual survey of the city's best and worst public washrooms.

Hoi Hing Road public toilet in Tsuen Wan won top recognition, judged according to the association's CASH formula, which measures Comfort, Accessibility, Safety and Hygiene.

"It's very clean, and also very easy to go in to the toilet, and it's safe - that means the floor is not wet - and very hygienic. Most of the taps, or all of the taps, are using sensor control - no need to touch the toilet or the tap," said Hung.

By contrast, Hung said the worst toilet was in Tsuen Wan Market, describing the washroom as dirty, smelly, with rusty facilities and a wet floor.

"We asked the government to take action as soon as possible."

Hung said over the past 10 years, after the government had injected about HK$6 million into refurbishing some 200 toilets, the image of the public facilities had greatly improved.