A major health scare has been sparked in Australia after workers were showered in deadly asbestos dust during the building of a new children’s hospital.

The initially unidentified material was disturbed when an employee drilled into one of 150 roof panels supplied by a Chinese company for the £688m Perth Children’s Hospital in Western Australia.

Suspicions were aroused and tests confirmed the material was chrysotile, also known as white asbestos.

The plant room on Level 8 of the hospital was sealed off and all the remaining roof panels were sealed.

Although the health authority insists that construction giant John Holland, which is the managing contractor for the project, took the correct action over the exposure, press reports have quoted workers criticising what they described as a slow response.

One told a radio station he had driven home still covered in the dust and had cuddled his two-year-old daughter.

But the firm insisted that the process of checking the samples for the presence of asbestos took less than an hour after the issues was raised. At that point it was decided to evacuate the area.

Tests on airborne samples found no traces of asbestos and the site was ruled to be safe, enabling the 200 employees to return to their jobs.

Workers are being offered information sessions with an industrial hygienist and will be given health checks if required, while the firm has offered to replace tools and clothing. Four employees asked for their cars to be tested but no asbestos was found.

The company rejected press reports that asbestos had been found in the ventilation system.

John Holland also said the Chinese firm, Yuanda, had provided certification stating that the panels did not contain asbestos.

In a statement on its website, the Child and Adolescent Health Service (CAHS) said: “The progress surrounding this issue is being monitored daily and every effort is being made we ensure we can safely maintain the hospital’s opening schedule.

“The presence of asbestos is totally unacceptable to CAHS and products containing asbestos are illegal in Australia. An investigation into the supply chain will be carried out, along with an audit of all other imported building materials used in the project.”

Extensive tests in other areas of the hospital site have all proved negative. National and state government authorities have been called in and the Building Commission has launched an inquiry.

John Holland is one of the country’s leading engineering, contracting and services providers with more than 65 years of experience.

Anthony McCarthy, an asbestos expert at Macks Solicitors, said that although the incident had happened in Australia, it underlined the need to remain vigilant about the ever-present dangers of asbestos.

“It’s easy to imagine that this is a problem that belongs firmly in the past,” he said. “Unfortunately, cases such as this one show that this isn’t the case.

“So many people still suffer unimaginable health problems from exposure to asbestos during their working lives. There are no longer any excuses for continuing to use the material and prolonging the misery for yet more families into the future.”