MIB is not harmful to human health and has no public health significance

Irish Water confirmed last month that following specialist testing of drinking water in the Dublin area, results indicated the presence of very low levels of a naturally occurring substance called MIB (2-Methylisoborneol). Further testing has shown that MIB levels have now reduced significantly.

MIB is a naturally occurring organic substance produced by algae found in lakes, rivers, streams and reservoirs. While MIB can result in some people detecting an earthy, musty smell and taste from their drinking water, it is not harmful to human health and, according to the World Health Organisation Guidelines for Drinking-water Quality, MIB has no public health significance.

Irish Water can confirm that drinking water microbiological and chemical analysis carried out on water produced at our water treatment plants serving the Greater Dublin Area is compliant with drinking water regulations. Water produced at our treatment plants is tested daily, in conjunction with extensive monitoring in the distribution network, and is safe to drink.

Irish Water’s primary focus is the protection of public health and we would like to reassure customers that the water coming from all of the drinking water plants serving Dublin is safe to drink.

Further information on drinking water quality can be found on our Drinking Water Quality section and information relating to taste and smell of water can be found on our Taste and Smell page.

Customers with queries or concerns about the quality of their drinking water should contact Irish Water directly on our customer care helpline, open 24/7, on 1850 278 278. 

Previous Updates

MIB is not harmful to human health and has no public health significance

Irish Water can confirm that specialist testing of drinking water in the Dublin area has indicated the presence of very low levels of a naturally occurring substance called MIB (2-Methylisoborneol). 

MIB is a naturally occurring organic substance produced by algae found in lakes, rivers, streams and reservoirs. While MIB can result in some people detecting an earthy, musty smell and taste from their drinking water, it is not harmful to human health and, according to the World Health Organisation Guidelines for Drinking-water Quality, MIB has no public health significance.

Irish Water can confirm that drinking water microbiological and chemical analysis carried out on water produced at our water treatment plants serving the Greater Dublin Area is compliant with drinking water regulations. Water produced at our treatment plants is tested daily in conjunction with extensive monitoring in the distribution network and is safe to drink.

Tom Cuddy, Asset Operations Support Services Manager

Speaking about the detection of MIB in the drinking water, Tom Cuddy, Asset Operations Support Services Manager, Irish Water said “Our primary focus is the protection of public health and we would like to reassure customers that the water coming from all of the drinking water plants serving Dublin is safe to drink. We understand the concerns raised by some customers in relation to the smell or taste of their drinking water, however MIB is not toxic or harmful and the water remains safe to drink. As a precaution, we have increased testing on the supply and will keep the situation under review.” 

More information

Further information on drinking water quality can be found on the Drinking Water Quality section of our website and information relating to taste and smell of water can be found on our Taste and Smell page.

Any customers with queries or concerns about the quality of their drinking water should contact us on 1850 278 278.

Dublin, Kildare

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