Workers suffered acute methyl bromide poisoning because of the way they worked or due to ineffective RPE, Poutasi said.
"Flick Anticimex was advising workers with facial hair to use Vaseline to help the mask fit on their face.
"This is a myth which is deeply concerning in how widespread it is. Businesses and organisations must stop propagating this myth."
Workers should have been clean shaven because even a small amount of facial hair could prevent a proper protection with RPE, he said.
Despite a health consultant in 2019 advising the business on proper RPE care, WorkSafe found that it was standard practice for the workers not to use RPE during fumigations and no staff had been properly trained to clean and maintain their equipment.
There was also no coherent system in place that monitored employees' exposure to toxic fumigants.