Staff at the nation's broadcaster have been told they're no longer allowed to use hair straighteners while at work.

The memo, titled "Hair straighteners must not be used on our premises" was sent around the building as pressure is heaped on broadcasters as the Rugby World Cup swings into gear and rival Spark battles with streaming issues.

However, TVNZ's ban appears to be front forwarding another possible disaster after the headquarters in Auckland central were evacuated mid-broadcast of Seven Sharp in May.

The incident was also referred to in the memo, a portion which reads, "As a live TV production environment, it's critical that we minimise the risk associated with using electrical devices. As well as the risk to safety and property damage, the operational risk to our live productions is considerable [you will all remember the sandwich press incident]".

A portion of the TVNZ memo sent out to staff.
A portion of the TVNZ memo sent out to staff.

The use of the popular hair appliance is now restricted to the company's Hair and Makeup team.

When contacted, a TVNZ spokeswoman said they were "looking to reduce non-essential electrical equipment to mitigate any risk of taking us off air".

"We were taken off air earlier this year and we have a lot of live broadcasts going on at the moment, so we're just being extra careful."

As well as the sandwich press incident, a small electrical fire saw TVNZ's Auckland newsroom evacuated and 1News' 6pm bulletin delayed for half an hour last year in January.

In that instance, alarms sounded at the Hobson St building about 5.30pm, sending scores of staff onto the streets where they huddled under their umbrellas until the all-clear was given.

Fire and Emergency NZ assistant area commander Glenn Menzies said the fire was located in the server room.