Worksafe's involved in an investigation, after several Christchurch Hospital staff fell ill, due to toxic fume exposure

On-site construction work is paused, after a number of radiology workers suffered breathing problems, rashes and headaches from a chemical used in paint work.

One staff member has been hospitalised, while there's been no reports of patients being affected.

Worksafe was notified in August, and are carrying out an investigation with Health NZ.

Health NZ deputy chief executive Martin Keogh says it's deeply concerning, and construction won't resume until the working environment is safe.