"When your school is struggling to provide you with a clean, safe and dry workspace at a minimum, and you are dealing with kids with more complicated needs - it all adds up," said Angela Roberts, president of the Post Primary Teachers Association (PPTA).
In New Zealand, injuries are the major cause of hospitalisation and death for school-aged children, and ACC has specific programmes aimed at reducing school accidents.
Principals' Federation president Phil Harding said schools were closely monitored for safety, and the increase could reflect people reporting injuries more willingly.
"Caretakers go around every week and there's a full schedule that demands people check playgrounds for sticking up nails, or chains that are worn."
There has been a recent push-back against an over-cautious health and safety culture by some schools, with an increasing body of research highlighting the importance of "acceptable risk" in play.
One Christchurch Intermediate has even successfully re-introduced unsupervised bullrush, a popular move with both students and parents, and Mr Harding said it was important to strike the right balance.
According to the ACC figures, the single biggest cause of injury to pupils was a loss of balance or personal control, resulting in 21,397 claims.
Another 10,973 injuries were caused when students were knocked over by an object or hurt in a collision. The third most common cause was what ACC termed "struck by person or animal" at 8,177 injuries.
ACC noted that such claims did not necessarily relate to deliberate physical assaults, and included instances such as insect bites and unintentional contact, such as being knocked over while playing.
More unusual injury causes included 39 cases of fire, 13 of explosion/blasting/implosion, five shooting incidents (which can include toy guns), five cases of electrical shocks, and a handful of "oral ingestion of fungi".
The most costly single accident to date for a student in the last financial year was $98,533, and for a teacher $127,348.
The biggest cause of injury for staff was lifting or carrying, at 1211 injuries.
More than 360 injuries were classed as "struck by person or animal" or "struck by held tool/implement".
Ms Roberts said that while many of those incidents would be unintentional, the PPTA encouraged its members to report any assaults, as this often ensured the student had access to the necessary health and welfare support.
