The Federation of Trade Unions on Monday urged the government to provide clearer guidelines of work arrangements under "extreme conditions", such as recently when adverse weather hit.

Under Labour Department guidelines, workers other than "designated staff" should stay in safe places rather than reporting for work as usual.

A two-hour leeway should also be given, under the guidelines, for employees to return to their places of work after extreme weather signals are lowered.

The federation's call came after a survey of about 620 workers in July and August found that over 60 percent of them had to report for work even when the black rainstorm warning signal and storm signal No 8 or above have been issued.

Lawmaker Kwok Wai-keung said more concrete definitions are needed for "designated staff" in different industries as many employees are unclear of what to do during such weather conditions.

"As we know, the recent regulations are only instructions," he said in a press briefing.

"Employees are confused [by] designated person, the definition is very difficult ...

"I think the government would like to think that the designated persons should involve some emergency industries, such as hospitals, police or firemen.

"But, as we know, most people who work in the catering industry or security industry also have to work during extreme weather," he added.

Kwok said the government should take a more proactive approach towards defining such personnel, such as asking employers about their operations under adverse weather conditions, then carry out reviews and provide a clear definition.

Employers, the federation said, should be more considerate and avoid meting out any punishment or docking leave if staff cannot get to work on time even after a bad-weather situation improves.

The call comes in wake of the issuance of five black rainstorm warning signals since July 29. The most recent black rainstorm signal was in force on Thursday for more than three hours and lowered at 11.10am, with staff expected to return to their workplace at 1.10pm, according to government guidelines.

The Code of Practice in Times of Adverse Weather and “Extreme Conditions” was updated in April 2024, after Hong Kong was hit by a so-called "once-in-a-century" rainstorm in September 2023.