# 9.10.3 Detection limits Ideally, the detection limit of the analytical method used should be lower than the level at which the characteristic might become a health concern. A health-based guideline value usually provides a benchmark against which the detection limit of the analytical methodology can be measured. If the methodology cannot achieve such a detection limit, there will inevitably be some difficulty or imprecision in assessing risk, and efforts should be made to find a more sensitive analytical method. Some fact sheets mention limit of detection (LOD) whilst others refer to a limit of quantitation (LOQ). The LOD is normally used to indicate the lowest level that can be reliably detected, while the minimum level than can be reliably quantified (LOQ) is often somewhat higher than the LOD. The advice of an analyst should be sought when selecting the analytical method to be used. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://guidelines.nhmrc.gov.au/australian-drinking-water-guidelines/part-3/chapter-9/9.10-reliability-of-monitoring-data/9.10.3-detection-limits.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.