WorkSafe chief inspector Keith Stewart said there was a similar accident at Juken in 2012.
"It is critical that companies review health and safety incidents and ensure similar events don't happen again," Mr Stewart said.
"For this type of accident to be repeated indicates a significant failure on behalf of the company to learn from a previous accident."
Juken could not immediately be reached for comment but a company website said Juken employed nearly 900 people at "four modern, efficient and environmentally clean" wood processing mills.
"We believe that a safe and healthy work environment is a basic and essential requirement of being a good employer, and a key ingredient in producing good products," the company added.