IT was disappointing to read yet another myth about banned chemicals and procedures (Teacher magazine, June 14). It is not true that there is a ban on making iodide in schools. Although it is possible that the odd employer may have banned it, I do not know of any.
It is true that lead salts are toxic, and need to be handled with care. But very dilute solutions are not classed as toxic and the experiment can be conducted at such concentrations. Perhaps there are schools where behavioural issues are such that a risk assessment would conclude that it was inadvisable to do this experiment but, as for being banned - rubbish!
Unfortunately, teachers reading an otherwise interesting article may now believe they are no longer permitted to carry out a common science activity. It is doubly disappointing after the article in Science Curriculum Special (December 28, 2001) pointing out that most of the alleged bans were, in fact, myths.
Dr Peter Borrows
Consortium of Local Education Authorities for the Provision of Science Services
Brunel University, Uxbridge
