The final guideline technical document of the Guidelines for Canadian Drinking Water Quality for toluene, ethylbenzene and the xylenes is now available on Health Canada's web site. CWWA commented on the guidelines when they were proposed, supporting the recommendations. There is also a wealth of background information on the substances and current research on their impacts which is an invaluable resource. The Guidelines are summarized below. 

 

• Toluene: A maximum acceptable concentration (MAC) of 0.06 mg/L (60 µg/L) is established for toluene in drinking water. An aesthetic objective (AO) of 0.024 mg/L (24 µg/L) is also established for toluene in drinking water.
• Ethylbenzene: A MAC of 0.14 mg/L (140 µg/L) is established for ethylbenzene in drinking water. An AO of 0.0016 mg/L (1.6 µg/L) is also established for ethylbenzene in drinking water.
• Xylenes: A MAC of 0.09 mg/L (90 µg/L) is established for total xylenes in drinking water. An AO of 0.02 mg/L (20 µg/L) is also established for total xylenes in drinking water.