Labour Dept on possible revision of city's heat stress warning

Commissioner for Labour Sam Hui says the heat stress at work warning system could be further refined before next summer.

However, he says the government will not consider directly adopting the internationally used WBGT index.

The government’s recent revision of the heat stress at work warning system has lowered the thresholds for triggering the advisories with red and black warnings possibly hoisted for a combined total of nearly 10 days each year.

Commissioner for Labour Sam Hui says the new mechanism should provide greater protection for workers, but the department will assess its effectiveness and consider further improvements.

He says the department will examine whether additional elements should be incorporated into the heat stress warning system before next summer.

But even so, Hui says the department will not simply switch to Wet Bulb Globe Temperature or the WBGT heat stress meter, as suggested by several former Hong Kong Observatory directors.

He says the government’s approach is to combine the strengths of different assessment tools, as each individual method has its limitations.

He says relying solely on WBGT could reduce sensitivity to heat stress caused by factors including air movement and humidity.

And they want their index to comprehensively protect workers in different environments – whether they are working outdoors under the scorching sun or indoors without air conditioning, where heat dissipation can be difficult.

Meanwhile, on whether heatstroke should be classified as an occupational disease to strengthen worker protection, Hui says such a classification requires medical evidence establishing a causal link between a worker’s health condition and specific working conditions or work patterns.

He acknowledges proving such a link would require further work, but says the government is willing to explore the possibility.