Asbestos prosecution unlikely at Aberystwyth hospital
A health board is unlikely to face prosecution over whether up to 30 people were exposed to asbestos at Bronglais Hospital in Aberystwyth.
The Health and Safety Executive said a failure to transfer criminal liabilities after NHS reforms in 2009 reduced the chance of success in court.
Construction union UCATT has called for an inquiry and said the workers were being denied justice.
The Welsh Government said it had received a letter about the issue.
Hywel Dda Health Board announced on Wednesday that up to 30 maintenance staff could have been exposed to asbestos at Bronglais Hospital.
It is trying to trace former workers and is offering screening tests.
The health board said asbestos had not entered public areas and patients and visitors were safe.
The problem at Bronglais Hospital occurred between 2004 and 2009, before the health board's formation.
Health boards replaced NHS trusts in Wales in October 2009.
Confirming there had been breaches of health and safety legislation at Bronglais, the Health and Safety Executive (HSE) said there was no prospect of a successful prosecution.
A spokesperson said: "HSE has investigated the matter and has concluded that breaches of health and safety legislation had occurred.
"However, having sought independent legal opinion, we have concluded that the failure to transfer criminal liabilities from NHS trusts to the successor health boards means there is no prospect of a successful prosecution.
"Had criminal liability been transferred then HSE would have prosecuted Hywel Dda Health Board for the historical failures to manage asbestos between 2004 and 2009."
UCATT said it had written to the First Minister Carwyn Jones demanding an inquiry into how the "legislative blunder" occurred, and is calling for "urgent action to reverse the problem".
Regional secretary for Wales and the south west, Nick Blundell, said: "This is an intolerable situation.
"Workers have been systematically exposed to asbestos and yet they will be denied justice due to a bureaucratic muddle.
"Carwyn Jones needs to act quickly to resolve these problems in order to restore confidence among workers."
Hywel Dda Health Board referred media inquiries to the Welsh Government.
A Welsh Government spokesperson said: "We have received the letter and will respond directly to the correspondent in due course."
Asbestos is a problem when fibres become airborne and are inhaled, and can lead to life-threatening illness.