Some Canada Post workers in Halifax briefly walked off the job Wednesday morning over concerns of unsafe working conditions following a chemical spill.

The incident happened at the post office and sorting facility on Almon Street when a shipment of pH Down was spilled in an area where employees were performing their regular work duties.

pH Down is an acid-based chemical liquid used to lower acidic levels and is often used in fish tanks and swimming pools.

When workers saw fire crews arrive to clean up the spill, they invoked their right to leave the workplace over safety concerns.

Jim Gallant, a grievance officer with the Canadian Union of Postal Workers, says there was a disagreement over the danger of exposure.

“There was definitely a disagreement between 7:30 and 10 o’clock because the employer didn’t want us to leave. But now the employer says, ‘You’ve done the right thing, we’ve shut down the plant and everything is good,’” says Gallant.

“Our position is that no, it’s not good. If this was a coal mine it would have blown up by now. We need to get out when the problem happens.”

It is believed the product was being shipped in a package.

The building reopened once the spill was contained and cleaned up. Staff returned to their duties just before 10:30 a.m.