Scientific Opinion on the minimum hygiene criteria to be applied to clean seawater and on the public health risks and hygiene criteria for bottled seawater intended for domestic use
Microbiological hazards have been associated with seawater. Poor quality sea water may consequently have a severe impact on public health. Coastal sources used for abstraction of seawater cannot be classified as a pristine source. The use of water safety plans, combining sanitary surveys with microbiological criteria and appropriate water treatment, is proposed in order to ensure adequate hygiene conditions and to control hazards. The comprehensiveness of the sanitary survey, the stringency of microbiological criteria, and the need for treatment depend on the relative exposures associated to the different uses of seawater. For uses with low exposure to microbiological hazards, a basic sanitary survey and microbiological criteria based on the Directive 2006/7/EC are considered appropriate. For uses with a higher exposure, a more comprehensive sanitary survey, mandatory water treatment, and microbiological criteria based on Council Directive 98/83/EC with an additional criterion for Vibrio spp. are considered appropriate. For uses with highest exposure, a more comprehensive sanitary survey, mandatory water treatment, and microbiological criteria based on Council Directive 98/83/EC with an additional criterion for turbidity and Vibrio spp. are considered appropriate. Both inorganic and organic chemicals can be found in seawater in concentrations that are usually low. Therefore the use of seawater on fresh or processed fishery products or for re-vitalisation of live molluscs is unlikely to raise a health concern. A potential health concern may occur from the domestic use of bottled seawater where human exposure might be expected to be higher than for the other uses of seawater. Therefore, the concentration of chemicals in bottled seawater should comply with the standards laid down in Council Directive 98/83/EC on the quality of water intended for human consumption. It is recommended to use ultraviolet (UV) or other physical methods as the preferred disinfection process to prevent the formation of hazardous disinfection by-products such as bromate and trihalomethanes.