Raac was used mostly in flat roofing, but also in floors and walls, between the 1950s and 1990s. It is a cheaper alternative to standard concrete, but is also less durable and has a shorter lifespan.

Last year schools, hospitals and other buildings including markets were among the buildings in Wales found to contain the material.

This included Withybush Hospital, where a major incident was declared and six wards, as well as other areas, were forced to close.

The six wards reopened in April, while other areas such as outpatient clinics and kitchens have also returned. Other departments, such as those used for physiotherapy and pharmacy, are expected to reopen in the coming weeks.

Sarah Davies, a nurse who works on one of the reopened wards, said “it feels so good to be back”.

“You can hear the alarms going off now. It’s just nice to have noise here,” she said.

A&E sister and clinical lead Lea Jones said it had “been slightly easier” since they reopened.

“But we’re going back into winter pressures now, so we always have problems this time of year anyway – it has been easier for us knowing that these wards are back open.”