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Document ID ca-gcdwqgtd-2015-04-24-9 Title Guidelines for Canadian Drinking Water Quality: Guideline Technical Document – Selenium URL https://www.canada.ca/en/health-canada/services/publications/healthy-living/guidelines-canadian-drinking-water-quality-guideline-technical-document-selenium/guidelines-canadian-drinking-water-quality-guideline-technical-document-selenium-page-11.html Jurisdiction /ca Subdomain(s) Drinking water, Water quality standards Language en Status completed Analyzed at 2026-03-18 16:22:49.412577+00:00 Relevance Technical guideline defining health-based limits for selenium in drinking water.
0 Qualitative 33 Quantitative 24 Definitions

Q Qualitative Requirements (0)

No qualitative requirements.

P Quantitative Requirements (33)

Req ID Category Intent Legal Status Name Subdomain(s) Limit Type Limit Value Context Conditions Confidence
#P001chemicalhealthrecommendedSeleniumdrinking waterrequirement15-55 µg/dayRecommended daily intakes (RDA) adopted by Health Canada in order to protect the Canadian population from selenium deficiency diseases.Depending on the age group.high
#P002chemicalhealthguidelineSeleniumdrinking waterrequirement400 µg/dayHealth Canada has adopted IOM's Tolerable Upper Intake Level (UL) of 400 µg of selenium per day.high
#P003chemicalhealthguidelineSeleniumdrinking waterrequirement0.05 mg/LHealth-based value (HBV) for selenium in drinking water. Calculated as 0.053 mg/L, rounded to 0.05 mg/L.Derived using a UL of 0.4 mg/day, a 0.20 default allocation factor for drinking water, and 1.5 L/day daily volume of water consumed by an adult.high
#P004chemicalhealthmandatorySeleniumdrinking waterMAC50 µg/LCurrent U.S. EPA maximum contaminant level (MCL) for selenium.Equals the maximum contaminant level goal (MCLG).high
#P005chemicalhealthguidanceSeleniumdrinking watertreatment_goal30 µg/LCalifornia Office of Environmental Health Hazard Assessment (OEHHA) public health goal (PHG) for selenium in drinking water.high
#P006chemicalhealthmandatorySeleniumdrinking waterMAC50 µg/LCalifornia's current standard (MCL) for selenium, adopted in 1994.high
#P007chemicalhealthguidelineSeleniumdrinking waterrequirement40 µg/LWorld Health Organization (WHO) provisional drinking water guideline value.Based on Institute of Medicine's UL of 0.4 mg/day, 20% allocation factor, and 2 L/day consumption.high
#P008chemicalhealthguidelineSeleniumdrinking waterrequirement10 µg/LAustralian drinking water guideline for selenium.Based on a 10% allocation factor and assuming a 70 kg adult drinking 2 L of water per day.high
#P009chemicalhealthguidanceSelenium (MCLG)drinking watertreatment_goal50 µg/LU.S. EPA maximum contaminant level goal (MCLG) for selenium.Analytical methods and treatment technology do not pose limitations.high
#P010chemicalhealthguidanceSelenium (NOAEL - Health Canada)drinking waterrequirement0.8 mg/dayNo observed adverse effects level (NOAEL) for selenium used to derive the tolerable upper intake level (UL).Rounded by IOM (2000) from Yang and co-workers studies.high
#P011chemicalhealthguidanceSelenium (Uncertainty Factor)drinking waterrequirement2 unitlessUncertainty factor used by IOM and Health Canada to derive the UL from the NOAEL.Chosen to protect sensitive individuals and account for non-severe, non-reversible nature of toxic effects.high
#P012chemicalhealthguidanceSelenium (Allocation Factor)drinking waterrequirement0.20 unitlessDefault allocation factor for drinking water used in health-based value (HBV) derivation.Used as a floor value because drinking water is not a major source of exposure.high
#P013designhealthguidanceAdult Daily Water Consumptiondrinking waterrequirement1.5 L/dayThe daily volume of water consumed by an adult used in Canadian HBV calculation.high
#P014chemicalhealthguidanceNOAEL for California PHGdrinking waterrequirement0.015 mg/kg bw per dayNOAEL for toxic non-cancer effects (hair loss and nail damage) used to establish California's PHG.Based on Chinese population studies.high
#P015designhealthguidanceDaily volume of water consumed (WHO)drinking waterrequirement2 L/dayConsumption value used by WHO to establish its provisional drinking water guideline.high
#P016designhealthguidanceDaily volume of water consumed (Australia)drinking waterrequirement2 L/dayConsumption value used for the Australian drinking water guideline calculation.Assuming a 70 kg adult.high
#P017chemicalhealthguidanceAllocation factor (Australia)drinking waterrequirement10 %Allocation factor used for the Australian drinking water guideline value.high
#P018designhealthguidanceAdult body weight (Australia)drinking waterrequirement70 kgBody weight parameter used in the Australian drinking water guideline derivation.high
#P019chemicalhealthguidanceBlood selenium concentration (no symptoms threshold)drinking waterrequirement<= 1000 µg/LThreshold below which selenosis symptoms were not present in the Chinese population study by Yang et al.high
#P020chemicalhealthguidanceMinimum selenium intake causing toxicity (Yang)drinking waterrequirement910 µg/dayIdentified as the minimum selenium intake causing toxicity in persistent selenosis cases.Corresponds to a blood selenium concentration of 1054 µg/L.high
#P021chemicalhealthguidanceBlood selenium concentration (symptom induction range)drinking waterrequirement1000-2000 µg/LConcentrations observed to induce symptoms in up to 35% of individuals in the Yang study.Chronic exposure to high levels of selenium.high
#P022chemicalhealthguidanceBlood selenium concentration (high symptom induction range)drinking waterrequirement2000-3300 µg/LConcentrations observed to induce symptoms in 45% of individuals in the Yang study.Chronic exposure to high levels of selenium.high
#P023chemicalhealthguidanceMaximum daily safe intake (Yang initial estimate)drinking waterrequirement750-850 µg/dayInitial identification of maximum daily safe intake of selenium by Yang and colleagues.Based on questionnaire distribution and food measurement in Chinese population.high
#P024chemicalhealthguidanceNOAEL mean intake (Yang follow-up)drinking waterrequirement819 µg/dayMean intake corresponding to dropped blood selenium levels where symptoms disappeared.Identified as the NOAEL by the authors after a follow-up of five recovered individuals.high
#P025chemicalhealthguidanceBlood selenium concentration (Safe maximum intake equivalent)drinking waterrequirement0.559 mg/LBlood selenium concentration corresponding to the identified safe maximum daily intake of 400 µg/day.Calculated after accounting for interindividual variations.high
#P026chemicalhealthguidanceNon-observed effect exposure level (Longnecker)drinking waterrequirement724 µg/dayExposure levels where selenosis symptoms were not observed in areas with high selenium levels.high
#P027chemicalhealthguidanceBlood selenium concentration without symptoms (Lemire)drinking waterrequirement1500 µg/LBlood selenium concentrations where selenosis symptoms were not observed in study areas with high levels.high
#P028chemicalhealthguidanceAverage selenium intake (South Dakota/Wyoming study)drinking waterrequirement0.24 mg/dayAverage intake by individuals in high-selenium regions over a 2-year period with no observed effects.Basis for the Australian drinking water guideline value.high
#P029chemicalhealthguidelineAllocation factor (WHO)drinking waterrequirement20 %Allocation factor used by WHO for establishing its provisional drinking water guideline.Based on 2 L/day consumption and UL of 0.4 mg/day.high
#P030chemicalhealthguidanceBlood selenium concentration (persistent symptoms)drinking waterrequirement1054-1854 µg/LRange of blood selenium concentrations observed in five Chinese individuals with persistent selenosis symptoms.Main source of selenium was plant-based food.high
#P031chemicalhealthguidanceBlood selenium concentration (symptomatic phase average)drinking waterrequirement1346 µg/LAverage blood selenium concentration in five patients during the symptomatic phase of the study.high
#P032chemicalhealthguidanceBlood selenium concentration (asymptomatic phase mean)drinking waterrequirement968 µg/LMean blood selenium concentration when symptoms had disappeared after diet improvement.Corresponds to a mean intake of 819 µg/day.high
#P033chemicalhealthguidanceMinimum blood selenium concentration causing toxicity (Yang)drinking waterrequirement1054 µg/LIdentified by Yang and colleagues as the minimum blood selenium concentration causing toxicity in persistent selenosis cases.Corresponds to a calculated intake of 910 µg/day.high

D Definitions (24)

Req ID Category Name Context Confidence
#D001ULhighest level of nutrient intake that is likely to pose no risk of adverse health effects for almost all individuals in the general populationhigh
#D002tolerable upper intake leveltolerable upper intake level (UL)high
#D003health based valuehealth based value (HBV)high
#D004maximum contaminant levelmaximum contaminant level (MCL)high
#D005maximum contaminant level goalmaximum contaminant level goal (MCLG)high
#D006public health goalpublic health goal (PHG)high
#D007NOAELno observed adverse effects levelhigh
#D008UFuncertainty factorhigh
#D009RDArecommended daily intakehigh
#D010HBVhealth-based valuehigh
#D011MCLmaximum contaminant levelhigh
#D012MCLGmaximum contaminant level goalhigh
#D013PHGpublic health goalhigh
#D014Keshan diseasecharacterized by cardiomyopathyhigh
#D015Kashin-Beck diseasecharacterized by rheumatismhigh
#D016Selenosis symptomscharacterized by hair loss, nail anomalies or loss, skin anomalies, garlic odour of the breath, tooth decay and, more severely, disturbances of the nervous systemhigh
#D017Group 3not classifiable as to its carcinogenicity to humanshigh
#D018class Dnot classifiable as to its carcinogenicity in humanshigh
#D019class B2probable human carcinogenshigh
#D020WHOWorld Health Organizationhigh
#D021OEHHACalifornia Office of Environmental Health Hazard Assessmenthigh
#D022IARCInternational Agency for Research on Cancerhigh
#D023IOMInstitute of Medicinehigh
#D024allocation factorused as a "floor value," since drinking water is not a major source of exposure to selenium, and there is evidence of the widespread presence of selenium in one of the other media (i.e., food)high