AFTER DEBATES about knives and guns in the classroom, schools are turning their attention to another potential weapon - pencil sharpeners. Schools have complained of incidents where children unscrewed small blades and used them to slash others or themselves.

Although such cases a rare, a stationery company said this week that it had received sufficient complaints to make it redesign all of its sharpeners.

Maufacturer Helix hope to ease teachers’ nerves by bringing out a “tamper-proof” sharpener, featuring a special screw head that it claims cannot be removed, even with a screwdriver.

Some schools have been forced to ban pencil sharpeners altogether, although teachers’ unions have played down the problem. One of the most shocking cases took place last year, when teenager Shanni Naylor had 30 stitches in her face after being slashed with a pencil sharpener blade by another girl at school. The 12-year-old had gone to the aid of a boy who was being bullied at Myrtle Springs school in Sheffield.

Normanton junior school in Derby banned plastic sharpeners after children were found stamping on them to remove the blades.

Waterloo primary in Ashton-under-Lyne banned sharpeners after a pupil slashed another child’s neck.

Jon Burke, a spokesman for Helix, which sells two million sharpeners a year, said: “We had a lot of feedback from teachers and parents that this was a problem and developed the patented screw.” Helix was previously responsible for launching the shatterproof ruler and the “safety point”

compass during the 1980s. The sharp point disappears into the device if pushed into something with force.

Chris Keates, general secretary of the NASUWT teachers’ union, said craft knives taken from design workshops were a bigger threat. “Anything can potentially become an offensive weapon,” she said, “and teachers and schools are more and more aware of the risks of pupils misusing equipment.

In some ways, if you produce a tamper-proof pencil sharpener you lay down a challenge to the pupils.”

Jan Fry, deputy chief executive of parents’ group Parentline Plus, said improving sharpeners did not tackle overall issues of bullying.

“If it isn’t a pencil sharpener, it will be something else,” she said.

Laura Warren, of the National Confederation for Parent Teacher Associations, said: “Parents will welcome anything making children’s time at school safer.”

New laws came into effect last week giving teachers a clearer right to frisk pupils for weapons.