You want funnels for a model ship? A telescope? Just wait until a few toilet rolls run out, and use the cardboard centres. Unless, of course, you've been worried by Dr Ian Hosein of the Public Health Laboratory Service in Cardiff. Writing in the British Medical Journal he cited "the potential for rapid spread of enteric diseases in nursery and infant schoolchildren," and concluded that "the cardboard tubes should not be used."
Some teachers have been declining to use them for years and even Blue Peter has shied away from them. Others point out that in the average infant school there are many more obvious ways children can pass on this kind of infection. However, there is no shortage of alternatives, of which the ordinary kitchen roll is the most obvious.
Teachers, of course, have grown accustomed to making inventive use of whatever bit of debris comes to hand. I happen to know, for example, that the first person to actually make a silk purse out of a sow's ear was an ancient Greek primary teacher.
Having tried it herself at home first, she sent a note with the children the next day: "Dear Parents, Next time your slave kills a pig, don't let him throw the ears away. Send them in and the children will make lovely purses for their dinner money in design technology on Friday afternoon."
What are we to think of this urge to re-use simple throwaway materials? Is it a cheapjack approach that sits uneasily alongside the currently fashionable drive for quality? Or is there a more positive side to it? After all, not only does recycling appear in various forms in the national curriculum, but it is one of those Good Things that schools feel they should be doing. And thinking of other uses for common objects involves the kind of creative and inventive thinking that lies at the core of good classroom practice.
Michaela Fallon, art co-ordinator at Canon Maggs C of E Middle School in Warwickshire, is a strong candidate for the title of Primary Recycling Queen. Her classroom, which is alive with beautiful art work and colourful objects, is also an astonishing testament to her inventiveness in re-using everyday materials. On the wall is a life-size relief model of the digestive organs of the human body, made from old tights, bubble wrap and a second-hand T-shirt. Hanging from the ceiling are dozens of delightful fish, made by the children from plastic pop bottles. On a table by the side are electrical games and gadgets built into cardboard chocolate boxes.
"My angle is simple," she says. "It helps children to see that things can be used for different purposes, and that's important for them."
The savings for her school are substantial. The huge colourful mural in the hall, for example, cost a mere Pounds 6.75 in materials. And the school's Star Trek float in the carnival cost virtually nothing - "We built the Starship Enterprise from 12 big cornflake boxes and chicken wire. One of the parents gave us a white bee-keeper's suit which we stuffed with newspaper and made into a spaceman, with a helmet based on a cycle helmet." The parents are only too pleased to feel that they are helping.
Delighted though her headteacher may be, cost cutting is not Michaela's priority. She is much more interested in encouraging children to search for possibilities - "to be creative with materials, and to have the confidence to have a go."