Safety assessment schemes

This safety assessment scheme, which is still in wide use, has never been claimed to provide absolute safety (zero risk). There is, in fact, no scheme that could do so. But it does claim that any residual risk associated with exposures corresponding to an ADI is almost certainly very low(3,). This is probably the case for most types of toxic agents, but we have no method to determine whether it is. But because the scheme claims to provide an estimate of low risk exposures, it is, at least implicitly, a risk assessment scheme that makes no attempt to characterize the risk that remains at exposures said to be "acceptable". 

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. 

Serious questions can also be raised about the use of specific "safety factors" to establish ADIs without scientific evidence to support the magnitude of such factors. In fact, there is nothing but custom to support the use of any specific safety factor(3, ). Because it can also be reasonably argued that the selection of specific safety factors is a matter of policy, not science, the safety assessment scheme can be seen as a blend of scientific and policy decisions that cannot be easily separated. 

Finally, the scheme has generally not been considered, even by its proponents, appropriate to apply to carcinogens. This view may stem from the legal stricture (which exists in the United States in the form of the Delaney clause of the Food, Drug and Cosmetic Act) that no ADI can be established for a carcinogenic additive, in which case no safety assessment scheme is needed. On the other hand, it may stem from a scientific view that the mode of action of carcinogens is such... 

Under this broad concept of risk assessment are encompassed all of the essential problems of toxicology that traditional safety assessment schemes have dealt with, but they have been recast to provide a means for answering a different question — that Isr the question of risk. There are other Important differences as well. Risk assessment does not rely on the biologically and statistically dubious concept of a NOEL, but takes into account all of the available dose-response data. It treats uncertainty not by the application of... 

The safety assessment scheme outlined in Fig. 1 has been applied on many occasions to Type 1 GM plants but, as yet, not at all to the newer Type 2 plants which are still at the pre-... 

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. 

The Australia inventory is the Australian Inventory of Chemical Substances (AICS).1516 It was established for the purpose of implementing the Industrial Chemicals (Notification and Assessment) Act 1989. The National Industrial Chemicals Notification and Assessment Scheme (NICNAS) operates under the Act for the notification and assessment of industrial chemicals and is administered by the National Occupational Health and Safety Commission (NOHSC). The list contains over 40,000 substances which gets added to regularly. 

Office of Chemical Safety, National Industrial Chemicals Notification Assessment Scheme, Sydney, Australia... 

Safety pharmacology can be thought of as one of the key areas to be integrated with structural and biochemical evaluations in the complete safety assessment program (see scheme below). 

Under this scheme, a decision on acceptable exposures is made in the second step, and involves matters of policy quite distinct from those issues concerning the nature and magnitude of risk. Under this scheme, the role of the health scientist is far more restricted than it is in the traditional safety assessment described earlier. The health scientist is no longer responsible for assigning acceptable exposures. On the other hand, the scientist has a more demanding task than under the traditional scheme, because he or she is asked to make an explicit statement about risk. 

Critical elements include study population and size, formulations, treatment assignments, starting dose, dose escalation scheme, safety assessments and determination of MTD, and pharmacokinetic and pharmacodynamic evaluations. 

The scheme for safety assessment of repository of solidified radioactive materials is shown in Figure 4. 

The IMCA (International Marine Contractors Association) runs a self regulation competence assurance and assessment scheme (IMCA, 2003) to enable contractors to facilitate and improve safety in the offshore industry. This excellent framework enables contractors to assess and demonstrate to others the competence of safety-critical personnel. It also includes competency measmes for client s representatives. While it focuses on the offshore industry this is very relevant to coastal and maritime works. Further details including guidance, guidance for assessors, logbooks, etc. can be obtained fi om www.imca-int.com. 

If the type of scheme is unlike anything introduced before, it may be better to carry out a Road Safety Assessment rather than a Road Safety Audit. The Road Safety Assessment can be written less formally than a Road Safety Audit and can include a Risk Assessment of any elements of the scheme that may give cause for concern. 

The safety case is regarded as an increasingly important audit tool and of greater potential value than off-the-shelf safety audit schemes. Local managers are expected to undertake regular safety audits and are externally audited every three years. Railtrack s safety case is audited by its own auditors and also by the Railway Inspectorate, who assess Railtrack s procedures for auditing the train operating companies compliance with their safety cases (HSE, 1997 13 ff.). 

Another important follow-up to the publication of lEC 61508 is the development of conformity assessment schemes for safety-related systems... 

One consequence of the increasing realisation that competence has a direct impact on health and safety has been the development of conformity assessment schemes covering competence. Conformity assessment, in its generality, is an activity concerned with determining directly or indirectly that relevant requirements have been met, and is most commonly used to determine if a product, system, process or a person s competence meets a defined specification. In the context of this chapter, conformity assessment relates to the process of determining whether people working in the electrical or safety-related control systems sectors can perform to the required level of competence. 

As a final observation, it is clear that these conformity assessment schemes have their roots in trade issues rather than in health and safety, but there are undeniable benefits in the health and safety field. For example, certification and registration schemes in the building industries, including the electrical sector, are favoured as one means of countering the cowboys who charge... 

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