Apparently they can.

The Fair Work Commission has upheld the dismissal of a Western Australian dockhand who used colourful language towards his supervisor and colleagues on multiple occasions, even after the final written warning was given.

The commission found when the supervisor asked the dockhand to help another labourer, the dockhand responded: "get f---d" and "get the fat lazy c--t to do it".

On a separate occasion, the leading hand raised a safety issue and the dockhand responded by saying: "you're a dickhead. You are supposed to be a leader of this group. You're a cock."

The employee also had said to another supervisor to "f--k off" and "get f---ed twice" and, on a separate occasion, had said to the security guard to "f--- off".

When the employer Mermaid Marine Vessel Operations dismissed him, the dockhand brought an unfair dismissal claim.

Commissioner Bruce Williams found it was unacceptable for the dockhand to direct the swearing at his colleagues even though swearing was common as part of "everyday descriptive language" at the dock .

"There is a generally appreciated distinction between regularly using swear words as part of everyday descriptive language and swearing aggressively and malicious at another person," Commissioner Williams said.

HWL Ebsworth employment lawyer Brad Swebeck said the generational and cultural change in workplaces meant swearing in a threatening manner was no longer acceptable.

"Australians like to use their swear words but other people might find that really offensive and the employer has to deal with that," Mr Swebeck said.

"There's a new generation of workforce out there, what might have been acceptable 10 or 15 years ago may no longer be relevant," he said.

It is understood the sacked employee is considering an appeal of the commission's decision. He will have until October 3 to make an appeal.