More than 80 workers are refusing to use a troublesome kiln at Pan Pac Forest Products' mill, north of Napier.
The kiln has been repeatedly shut down due to health and safety breaches and concerns about the gas emissions. Last week four workers from the Whirinaki site required medical treatment.
Workers from the lumber division have issued a health and safety strike notice effective from 10am yesterday. They would not load wood into the Thermally Modified Timber kiln. The strike notice covered 85 union members.
First Union general secretary Robert Reid said members were fed up with repeated health and safety issues with the company's new kiln.
The kiln was introduced in April 2014, but a year later workers and the neighbouring community reported outbreaks of rashes, breathing problems and other ailments that they feared were linked to emissions from the kiln.