Employees at an addictions centre in St. John's are refusing to work because of chemicals used in construction of the building 50 years ago.
The eight workers - members of NAPE - work in a building in Pleasantville which houses the Rowan Centre, a methadone clinic and a centre for young people with addictions.
The union says since December, the workers have been worried about fumes coming from creosote in older parts of the building.
At the time, Eastern Heath relocated many of its staff, but not staff from the Rowan Centre or the methadone clinic because there is no creosote there.
The remaining workers have been worried about their health, and union officials have asked that they be relocated as well.
NAPE said the employees refused to report for work on Monday afternoon, citing their right to refuse work under the provincial Occupational Health and Safety Act, and after complaining to Eastern Health several times.
In a statement released later Tuesday, Eastern Health said it is surprised by the workers' actions. The health authority said there has been no evidence to suggest that the newer part of the building is unsafe, and an air quality test has been scheduled for the area in question.
The health authority has said that as long as those workers stay off the job, all services at the youth addictions centre, including some services at the methadone clinic, will be cancelled.