Market for tooth whitening products continues to be restricted in Europe

The long-awaited SCCP Opinion on Hydrogen Peroxide in Tooth Whitening Products opens the way for tooth whitening products containing up to 6% hydrogen peroxide to be available through dentists but not direct to consumers.

The European Commission Scientific Committee on Consumer Products (SCCP) adopted its opinion on hydrogen peroxide in tooth whitening products on 15 March 2005. This opinion may be accessed by clicking here. This will open a PDF in a new window.

The SCCP had invited interested parties to submit comments or pertinent scientific information regarding the "Preliminary Opinion on Hydrogen Peroxide in Tooth Whitening Products," by 31 January.

Approximately half of the 24 comments supported the notion that tooth whitening products should only be used after consultation with a dentist. Consumer and public health organisations, dentist organisations, as well as professionals in Scandinavia and Ireland supported this notion. Members of the cosmetics industry, as well as some individuals in the UK and United States, held the view that the products were safe and should be freely available.

Several of the comments received, especially from the cosmetics industry, referred to the possible carcinogenic effects of hydrogen peroxide in the oral cavity and enhancement by use of tobacco and/or alcohol. It was stressed by the SCCP that this was only one aspect in the Opinion. None of the comments argued against the SCCP conclusion re carcinogenicity, namely that hydrogen peroxide has a weak potential to induce local carcinogenic effects and may also act as a weak promoter.

The cosmetics industry argued that there are available over 100 published and unpublished clinical studies, comprising approximately 4000 subjects in total, and in addition, a 7.5-year follow-up study on a small group of tooth whitening products users. The SCCP maintained that only 9 of the 15 persons in the long-term study agreed to clinical examination. Six studies, all with less than 100 people, had up to 6 months follow-up and the majority of the studies seemed to be less than 1.5 months and involve less than 150 persons. The SCCP stated that for a case-reference study to detect a doubling of the risk for an adverse effect that occurs at a level of 1:1000 in the reference group, the study group must have at least 1000 people. Thus, the SCCP held there was still a need for good clinical studies during the use of tooth whitening products as well as long-term clinical data and epidemiological studies that assess the possible adverse effects of tooth whitening products within the oral cavity.

The SCCP was of the opinion that:

• The use of tooth whitening products up to 0.1% hydrogen peroxide is safe.
• The proper use of tooth whitening products containing > 0.1 to 6.0 % hydrogen peroxide (or equivalent for hydrogen peroxide releasing substances) is considered safe after consultation with and approval of the consumer's dentist.
• The body also recommends that such tooth whitening products are not used prior to or immediately after dental restoration and that care should be taken if dental diseases are present. Conditions such as pre-existing oral tissue injury or concurrent use of tobacco and/or alcohol may exacerbate the toxic effects of hydrogen peroxide.
• The SCCP concluded that there was a need for further clinical studies into the use of tooth whitening products, combined with the further study of long-term clinical data and epidemiological studies assessing any other adverse affects.
• The new additional data supplied does not provide the necessary reassurance in terms of risk assessment to support the safety of hydrogen peroxide up to 6% in tooth whitening products freely and directly available to the consumer in various application forms (strips, trays, etc.)
• SCCP cannot quantify the risk of potential serious adverse effects in relation to the use of tooth whitening products.

The SCCP's decision not to recommend the free consumer access of tooth whitening products containing 6 per cent or more hydrogen peroxide on the market is therefore based on the technicality of lack of clinical studies into the use of tooth whitening products, combined with the stated need for further study of long-term clinical data and epidemiological studies assessing any other adverse affects.

The SCCP Opinion will feed into the political decision making process which is likely to be based on the precautionary principle – the application of the precautionary principle was set out by the European Commission in their Communication of 2000 "The application of the precautionary principle is part of risk management, when scientific uncertainty precludes a full assessment of the risk and when decision makers consider that the chosen level of environmental protection or of human, animal and count health maybe in jeopardy." (European Commission Communication of 2000 p13)

The Commission's definition makes clear that a decision to act on the precautionary principle should be a political decision rather than a regulatory one. This is essential because of the conflicting issues present in any instance where there is an unquantifiable risk where steps taken will impact on an industry. The assessment of any uncontraviable risk needs to be viewed on an objective and complete scientific basis. The fact that this is a political decision therefore allows for flexibility and immediate decisive action where required.

This is unlikely to be the case in this instance, where it is likely that SCCP's Opinion will be taken as an opportunity for further delay in any extension of the market in tooth whitening products.