Water Sanitation Health

Chemical hazards in drinking-water - boron

Boron is considered in the WHO Guidelines for Drinking-water Quality. The Drinking-water Quality Committee, at its meeting of 9-13 November 2009, recommended revising the Boron Guideline Value to 2.4 mg/L. The revised Guideline Value and Summary Statement will be incorporated into the Guidelines for Drinking-water Quality, 4th Edition, which will be published in 2011.

The background document and a summary statement for the 4th Edition are now available.

The Guidelines for drinking water quality also consider for individual chemicals:

Rolling revision of the WHO Guidelines for Drinking-water Quality

Boron is included in the plan of work of the rolling revision of the WHO Guidelines for Drinking-water Quality.


The GDWQ FTF meeting (Geneva, 2003) recommended that boron be added to the rolling revision on the basis of new data and the assessment from the USA. The Expert Group on Guidelines for Desalination also recommended that the guideline for boron be reconsidered in the light of new thinking on the toxicity, as boron levels are quite high in seawater and boron removal is difficult.

Expected end-product(s)

Background document and summary statement for Fourth Edition

Progress to date

It was agreed that the need to review boron in the rolling revision would be considered once new data became available. The GDWQ WG meeting (Geneva, 2006) decided to reconsider boron for the Fourth Edition. The GDWQ WG meeting (Berlin, 2007) agreed on a path forward. The GDWQ WG meeting (Singapore, 2008) agreed to post the revised background document on boron to the web for public comment as soon as possible.

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