Almost half the day shift of workers at Highland Valley Copper put down their tools Wednesday in support of a health-and-safety representative who they felt was unfairly penalized.

The 300 United Steelworkers members got their representative's suspension lifted, along with the safety investigation he was calling for, but it doesn't end the union's concerns at Highland Valley, said local 7619 president Richard Boyce.

Wednesday morning's walkout was rooted in events from about six weeks ago, when a worker in the mill concentrator building was exposed to sulphur dioxide gas from a copper dryer.

He was taken to Royal Inland Hospital for SO2 poisoning.

Boyce said the injured man was a member of the mine's emergency response team, so he was aware of the danger of gases and sulphur dioxide in particular.

"It's not the first problem we've had in the mill with people being gassed with SO2. In the last six months, we've had four cases," he said.

After that incident, the union wanted an investigation to find out where the gas came from and why the SO2 detectors in the building didn't go off. Management disagreed, he said.

Boyce said the union has equal rights under the Health, Safety and Reclamation Codes for Mines in B.C. The co-chair of the health and safety committee wanted to start gathering information for an investigation, and looked at the SO2 detectors.

"We found all four were inoperable. They didn't work," he said.

A new maintenance manager at the mine got into a confrontation with the health and safety representative and said there would be no investigation. When the rep challenged the department manager, he was given four days' suspension.

That occurred Tuesday, said Boyce.

"So about 300 people put their tools down today and said they weren't going to tolerate it."

Boyce said when he went to the mine Wednesday to talk to the workers, they were clear they supported the representative.

By mid-afternoon, a resolution was reached. The company agreed to a proper investigation and to let the representative return to work Thursday. The copper dryer will not be run until the SO2 detectors are working.

Company spokesman Mark Freberg said he didn't have a lot of detail about Wednesday's walkout.

"Production hasn't been impacted at all so far," he said. Freberg was in Kamloops on holidays.

He didn't know how many workers are not working, nor did he have details about the employee's suspension.

He did say the last time a walkout of this type occurred was more than 10 years ago.

Boyce said the company is dealing with health and safety differently at the copper mine now and it's quick to blame workers for problems instead of managers.

"This particular issue is resolved for now. But I've received a number of phone calls saying this isn't the only issue why people are upset about health and safety at the mine," he said.

The man who was poisoned with SO2 a few weeks ago is OK, but a woman who was gassed some months ago is still having health problems, he said.