They also require schools to notify monitor and report on the use of physical restraint.
The guidelines say examples of a serious and imminent risk include:
* a student moving in with a weapon, or something that could be used as a weapon, and is clearly intent on using violence towards another person
* a student physically attacking another person, or is about to
* a student throwing furniture, computers, or breaking glass close to others who would be injured if hit
* a student putting themselves in danger, for example running on to a road or trying to harm themselves
While examples of behaviour that does not pose a serious and imminent risk include:
* behaviour that is disrupting the classroom but not putting anyone in danger of being hurt
* refusal to comply with an adult's request
* verbal threats
* a student who is trying to leave the classroom or school without permission
* a student who is damaging or removing property, unless there is a risk to safety
Newman said the problem with the guidelines was the wording.
"What is danger to other children? It's putting us into those grey areas and it's ridiculous because common sense has disappeared. The pressure is absolutely huge.
"You ring up any teacher and they'll tell you the biggest fear that they have is that they'll do something and end up in front of [the Education Council]."
Newman is not the only principal frustrated. He asked Northland principals to email him with problems they've had with the restraint rules and received numerous responses.
"A student who routinely trashed the classroom at any moment of upset or perceived slight.
"He was deliberate in how he did this. He was careful not to cause direct harm to other children or the teacher, but did set about destroying class property. He would sweep every book off the shelves, tip chairs and tables, rip displays off walls.
"The teacher would evacuate the class from the room, but the student would often choose to follow them outside," one principal said.
Another said of a student: "His behaviour in class can, without warning be extreme. He has urinated on the floor in front the class as an act of defiance, swears and spits at the teacher, destroys property in the classroom.
"On occasion, he screams for long periods of time. He regularly hits or kicks the teacher, as well as other students. While restraint 'may be' permitted if he is causing harm to others, it is his anti-social behaviour - peeing, swearing, screaming, destroying property - that we find particularly challenging to manage," another said.
Katrina Casey, Deputy Secretary Sector Enablement and Support, said the Physical Restraint Advisory Group was being reconvened to make the guidelines clearer and easier to use.
"It's important to note that the use of professional judgement is a critical part of the guidelines," she said.
