Four South Australian prison officers and one prisoner have received electric shocks from power points and intercoms tampered with by inmates lighting banned cigarettes.

Key points: Smoking was banned at Adelaide's Yatala Labour Prison in July

Smoking was banned at Adelaide's Yatala Labour Prison in July Prisoners have been sticking metal from food trays into power points to light makeshift cigarettes

Prisoners have been sticking metal from food trays into power points to light makeshift cigarettes Four prison officers and a prisoner have received electric shocks from tampered power points

The State Government said it had dealt with the problem by installing warning signs above prison power points.

The Public Service Association said the latest shock happened this morning at Adelaide's Yatala Labour Prison, where cigarettes were banned in July.

The prison officer is recovering in hospital after being shocked when he touched an intercom in a prisoner's cell.

The union said prisoners were making cigarettes from tea leaves and nicotine patches wrapped in pages from the Bible and then lighting them by sticking strips of aluminium foil into power points.

Prison officers had then been shocked when using the power points.

The signs warn people not to touch power points if they notice any protrusions from them.

Yatala Labour Prison is a high-security men's prison in Adelaide. ( ABC News )

Correctional Services Minister Corey Wingard said his department was also moving towards having plastic food trays and tamper-proof power points.

"What corrections are doing and have done is they have put warning signs above all the power points to make sure people are aware, to keep an eye out in case they have been tampered with," he said.

"They're also working on a prototype for a new power point that will specifically not be able to be tampered with and they're also working on transitioning their food trays from aluminium to plastic as well.

"So there are a number of measures in place, but I know the corrections staff are working very closely with the management as well to make sure we have as safe an environment as possible.

"That's something we're focused on in any workplace — to have a safe environment — and those measures have been put in place."

Problem not new to department

Union spokesman Austin White said the problem first arose at the Adelaide Remand Centre, after it went smoke-free in 2016.

Mr White said the remand centre now used plastic trays to prevent the problem, so it was hard to understand why similar measures were not also implemented at Yatala.

He also called for electrical appliances in cells to be hardwired instead of using power points.

"It's extremely dangerous, not just for the risk of electric shock," he said.

"It's also extremely dangerous because it creates a serious risk of fire and we don't want a situation where members, whose jobs are dangerous enough, to face the risk of electric shock or fire."

Mr White called for safety assessments to be conducted across all of the state's prisons.

"The department doesn't seem to prioritise staff safety, but that is our highest priority, and we need all steps taken to ensure staff prison officers' safety is protected," he said.

Mr Wingard said the union and staff supported prisons going smoke free.

"As the prisons have gone smoke free, it has worked very, very well," he said.

"The people have worked hard on making sure we keep the environment as safe as possible, but extra measures are being put in place."