Labour and welfare minister Chris Sun on Saturday played down the need for legally-binding guidelines to protect workers from heatstroke, saying incoming advisory measures will provide greater flexibility.

But he warned that people who violated such guidelines could be prosecuted.

A three-tier warning system that comes with amber, red and black alerts will be rolled out on May 15. Employers will be advised to take necessary measures to prevent workers from getting heatstroke if the warnings are triggered.

"When you look at the risk of heatstroke at workplaces, it varies a lot. Of course it depends on weather conditions, but also the very unique situation of each and every workplace, and the measures in place, they all have a role to play," Sun told reporters.

"For those who have clearly violated the guidelines in a blatant way, we can pursue them by using the employer's general duty under the law. Eventually, they are subject to legal punishment."

Sun also said he was deeply concerned following the death on Friday of a 64-year-old government worker from a bee sting.

"It's part of our overall system to ensure that workplace safety is given priority. The key is, for employers, they have to assess the risk of workplaces under their remit to make sure there are enough measures in place, to make sure that workers in these workplaces are given the adequate protection," he said.

On whether protective gear should be mandatory for workers who might be at risk of bee attacks, the minister said it would depend on the situation.

Separately, Sun said 17,000 out of around 27,000 applications for the government's Top Talent Pass Scheme have been approved, with about 5,000 of them already in the city.

The minister added that two-thirds of applicants came from the mainland.