Verification and Review of Standards

An assessment of whether a particular standard has met its original protection objectives should always be an integral part of the standard-setting process. This should be conducted along with a review of the standard should there be information that can be used to update it and increase overall confidence in its application. A stringent standard may be more likely to meet its protection goals, but it is also important to consider the social and economic aspects surrounding its implementation as it is also important that standards do not place unnecessary burdens beyond what may be required to achieve objectives. 

In light of this, it seems wise to build regular review into the implementation strategy for a standard so that users can determine whether the standard is 

In undertaking such verification of the usefulness and effectiveness of standards, it is necessary to take account of the potential for many interferences and confounding factors that affect real ecosystems. The ecosystems may be affected by climate, habitat, and contaminants other than those of interest to the study, thus making in situ or field assessment difficult. It is important, wherever possible, to avoid simply concluding that, regardless of whether the standard is passed or failed, environmental or ecological quality does not appear to be affected. 

Another form of verification of a standard that does not depend on possibly non-causal correlations between exposure to a chemical and biological effect is the use of controlled experiments such as aquatic mesocosms (see Section 4.7) and experimental field plots. Although such systems do suffer from certain drawbacks (e.g., Crane 1997), they may provide a valuable line of evidence if designed appropriately. 

Different lines of evidence from controlled laboratory, mesocosm, and field experiments and from uncontrolled field-based correlations can be used during periodic reviews in a weight-of-evidence approach to determine whether a standard is fit for use or should be relaxed or tightened. 

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