The Shop, Distributive and Allied Employees Association (SDA) says footage which shows a woman spitting on and yelling at workers at an Adelaide fast-food restaurant is 'vile' but not surprising.

The video, shared on social media page "S*** Adelaide", allegedly occurred at McDonald's Hindley Street Store, and shows a woman reaching over the counter before throwing drinks at a staff member.

She then accuses a staff member of assault, before spitting on them.

It comes weeks after South Australia introduced harsher penalties for people who assault retail workers.

The rules apply to anyone selling goods.

Perpetrators who attack retail workers will be handed the same punishments as those for assaulting a police officer or paramedic.

The changes have yet to pass parliament as legislation, but have been implemented by the state government as regulation.

SDA Secretary Josh Peak said he was not surprised by the incident. 

“Unfortunately, this sort of attack is not surprising – frankly, I’m sick of it occurring at this particular restaurant,” Mr Peak said.

“Should this have occurred during a known peak period, we have to wonder whether security were there and being provided by the employer, because we know that’s not always the case at this site.

“We do think Safe Work SA needs to take this seriously.

In a statement, a McDonald's Australia spokesperson said its employees deserved respect.

“The health and safety of our people and customers is our top priority," the spokesperson said. 

“Anti-social behaviour is not tolerated in our restaurants and we expect our people to be treated with respect at all times.

“We will always do our best for our customers, but we won’t accept abuse, intimidation, threats or violence towards our employees.

“We will continue to support all employees involved.” 

SA Police said it had been made aware of the footage, but said no charges had been laid in relation to the incident.