The answer is no longer as simple as it might once have been; coarse language has become increasingly commonplace in society. As a fair work commission explained last year, "there is no doubt that workplaces are more robust in 2015, as they relate to the use of swearing, than they were in the 1940s". Drawing the line between acceptable and unacceptable conduct is increasingly difficult.

Two recent private sector cases highlight this uncertainty. In Sayers v CUB Pty Ltd, a Carlton & United Breweries employee told a colleague "you are nothing but a dirty gringo c---" and "any place, any time, you name it, you are going down". After he was sacked on the ground of serious misconduct, Mark Sayers applied for unfair-dismissal relief.

Despite a rather creative application, which asserted that "gringo" was not intended as a racist slur because the target of the comment was South American, and the term is traditionally used by South Americans to disparage North Americans, Sayers' claim failed. Fair Work Commission deputy president Richard Clancy observed that "there is no place for behaviour in the workplace that combines threats of violence, racial slurs of such an offensive and degrading nature, and such inappropriate abuse and offensive language".

In contrast, in Goodall v Mt Arthur Coal Pty Ltd, a mining truck operator won reinstatement after his dismissal from BHP Billiton's Hunter Valley coal mine. Jodie Goodall had engaged in "banter and chat" over a radio system "as a means of dealing with fatigue" towards the end of a 12½-hour night shift. This "banter" included comments that a colleague was reading a book "on 50 ways to eat cock", that a colleague would "probably like a good tea-bagging" and that Muslims "had 1400 years of bloody inbreeding, so they gotta be f­­­­­­­----- up".

While fair work commissioner Tony Saunders held that these "substantial breaches" of the mine's policies provided a "sound, defensible and well-founded reason for dismissal", he nevertheless concluded that the dismissal had been harsh. Saunders noted that "profanities are commonly used" in the mining industry and most of the comments were of a low to mid-range on a scale of seriousness. In conjunction with several mitigating factors, Saunders concluded that while some form of disciplining was justified, dismissal was harsh and Goodall should be reinstated.

Had such conduct happened in an Australian Public Service workplace, the starting point would, of course, be the Public Service Act. The code of conduct provides that a public servant must "treat everyone with respect and courtesy, and without harassment".

Accordingly, the first question is whether the use of a swear word equates to acting without respect and courtesy. Telling a colleague to "f--- off" would likely fall foul of the code, but screaming "s---" after stubbing your toe is probably within safe bounds. While this may seem common sense, the middle ground is less clear and much will depend on workplace context. What may be permitted in one department may be considered out of line in another. The Public Service Commission is of the view that "maintaining courteous workplace behaviour is not meant to impose rigid rules on workplace styles, or on workplace relationships and social activities", and sensitivity to a particular office's culture is important.

Other relevant factors highlighted by employment tribunals include whether the comments were a regular occurrence or a one-off aberration, whether similar behaviour has been tolerated in the past, and whether the comments could cause any reputational damage (such as if an employee swore at a member of the public). It is also worth recalling that the code of conduct stretches beyond the workplace to actions done "in connection with employment", so swearing at a colleague during after-work drinks might be just as imprudent as doing so in the office.

We recommend human resources staff thinking carefully before bringing costly code proceedings against an employee for using foul language. When the swearing is aggressive or contains an element of racism or sexism, seeking to reprimand (and, in egregious cases, dismiss) the offending employee would normally be justified and legally defensible. On the other hand, less serious breaches might better be dealt with at a personal level without recourse to formalities – at least initially.

The code of conduct rightly promotes respectful and harmonious public service workplaces. But this sound principle should be implemented with humanity, proportionality and common sense. While the British judiciary might be caricatured as a bastion of tradition and civility, the Privy Council's pronouncements on this topic as far back as 1937 remain surprisingly apt.

"Their lordships would be very loath to assent to the view that a single outbreak of bad temper, accompanied, it may be, with regrettable language, is a sufficient ground for dismissal," Lord Maugham wrote. "In such cases one must apply the standards of men, and not those of angels."

John Wilson is the managing legal director at Bradley Allen Love Lawyers and an accredited specialist in industrial relations and employment law. He thanks Kieran Pender for his help in preparing this article. john.wilson@bradleyallenlove.com.au