Texas has scrapped a law that guaranteed construction workers in some cities the right to water breaks on the job, drawing anger Wednesday from unions and local authorities as much of America endured a brutal heat wave.

The new bill was passed by the state legislature and signed into law in mid-June by Governor Greg Abbott. It will take effect in September.

The bill's backers argue it returns regulatory powers to the state, as several local jurisdictions have established their own business rules that sometimes clashed with those of Texas.

The new law eliminates a provision that let construction workers in Austin and Dallas take water breaks every four hours and rest in the shade for 10 minutes.

"There are going to be many things that we don't know yet that will be impacted, but what we do know is that HB 2127 prohibits cities and counties from passing or enforcing basic protections," Ana Gonzalez, a representative of the AFL-CIO, America's main labor federation, said referring to the new law.

"We're experiencing extreme weather. There's been cases in parts of Texas where workers have died of heat-related illnesses. Texas is the deadliest state when it comes to construction," she told AFP.

On Monday, Houston Mayor Sylvester Turner said the city filed a suit seeking to prevent the state law from taking effect.

Gonzalez said federal government statistics show there were 42 heat-related deaths in Texas in the construction sector from 2011 to 2022. 

In the last two weeks of June, Texas and other parts of the US South suffered severe hot weather with temperatures up to 40 degrees Celsius (104 Fahrenheit). The heat wave was blamed for 13 deaths.

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