An investigation of the disposal of hazardous wastes from New Zealand dental practices.

A national survey was conducted to investigate current procedures in New Zealand dental practices for disposal of clinical waste. A questionnaire was sent out to all dental practices in New Zealand, and non-returns were followed up by two further mailings. From three mailings 767 useable questionnaires were returned (71.3% of those sent out, 79.0% of those potentially valid). Responses indicated that 56.4% of dental practices disposed of bloody swabs into the waste paper bin, and 24.4% disposed of contaminated sharp items into the general household refuse collection. Qualitative interviews with dental practitioners revealed a lack of concern about disposal of contaminated waste into the general waste. The existence of legislation governing waste disposal was not sufficient to motivate many practitioners to comply with guidelines. In some areas there was no specialised waste disposal service available, but some dentists had rejected a specialised service on the grounds of cost or inconvenience. Substantial efforts were made to salvage amalgam waste to be sold for scrap.