Safety assessment schemes limitations

The safety assessment scheme described above appears to have provided adequate public health protection, and will no doubt continue in use for some time to come. There are, however, certain limitations in the scheme that should be acknowledged. 

In the EU, the current chemical control measures, based on a network of legislation for hazard communication and safety assessment, are soon to be dramatically revised. To set the scene for this forthcoming fundamental change to chemical control in the EU, the key facets of the existing measures are described briefly i.e., notification of new chemical substances, the relatively-limited measures to evaluate existing substances and hazard communication. There have been problems with the current scheme, principally the disparity between the safety data on new and existing substances. 

There are a large number of different methods used for bench-scale assessment of combustion toxicity, and the applicability of test data to lire hazard assessment is not always clear. Obviously, toxic potency data should not be used in isolation but should either be a part of a classification scheme or as part of the input to lire risk and lire safety engineering assessments. It is important that uncertainty or confidence limits should be used with toxic potency data, because they are often relatively large. Fire effluent toxic potency does not have a unique value but is a function of the material and the fire conditions, particularly temperature and oxygen availability in the fire zone, and also the fire environment (enclosure, geometry, and ventilation). To assess the fire hazard, toxic potency data must be relevant to the end use fire situation, and the fire condition, which can be defined using the ISO classification of fire stages. 

Recognising the special difficulties for homoeopathic products to satisfy the standard requirements for proof of efficacy, the European Directive 92/73 was agreed and implemented in the UK with the Homoeopathic Registration Scheme. Under the scheme, efficacy is not a criterion of assessment, on the grounds that no therapeutic indications are claimed for the product and this must be conveyed on the label. Safety is assured by limiting the scheme to oral or external products and a sufficient dilution of the product technical data must be submitted to demonstrate adequate quality. 

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