Two companies, a host employer and a labour hire company, have been fined a total of $120,000 for an incident in which a worker's leg was severely injured and later amputated.

The companies pleaded guilty earlier this month to failing to ensure the provision of a safe workplace and, by that failure, causing serious harm to an employee.

The incident occurred in early 2008 when labour hire company Flexi Staff supplied two casual labourers to host employer Beds Plus in Kewdale.

It was not part of their labouring job to operate forklifts, and neither had any experience or qualifications or High Risk Work licences. However, after having been employed at the company for two to three weeks, they were given a short lesson by a supervisor and instructed to operate the forklift.

In March, one of the men unloaded a sea container and brought a pallet inside the warehouse using a forklift. He placed the pallet on the top level of shelving with the forks and mast fully extended.

He did not lower the forks and mast before driving towards the warehouse's roller door, which was raised between five and six metres. The mast struck the roller door and began to tip over, and the labourer attempted to jump from the falling forklift.

As the forklift fell, the man's right leg was trapped between the rollover protection structure on the forklift and the concrete floor. A second forklift was used to lift the forklift from the man's leg, which was later amputated below the knee.

According to acting WorkSafe WA commissioner Lex McCulloch, the case should serve as a reminder that both labour hire companies and host employers are responsible for ensuring a safe workplace.

"In this case, neither the labour hire company nor the host employer fulfilled their obligation to ensure, as far as was reasonably practicable, that the host workplace was safe for the workers sent to it."

"It is apparent that the worker was not given sufficient training and instruction on how to operate a forklift, an item of plant that requires operators to obtain a High Risk Work licence.

"High Risk Work licences have been introduced for a good reason, and that is to ensure that the people undertaking that work are trained to perform it in a safe manner for everyone concerned.

"On average, around 180 Western Australian workers are injured in incidents involving forklifts each year, and five WA workers have died in forklift-related incidents since 2004," he says.