Here below please find a summary of the World Health Organisation – WHO’s Guidelines for Drinking-water Quality, set up in Geneva, 1993. These standards are the international reference point for standard setting for drinking-water. For India these standards are set by the Bureau of Indian Standards – BIS, the erstwhile Indian Standards Institute – ISI.

The relevant BIS standard is BIS: 10500 available from the BIS site www.bis.org.in
For those of you interested in seeing the American Water Standards set by the internationally famous Environmental Protection Agency – EPA of USA, please visit the EPA site or get it from a Copy on our site.

Chlorine is widely to treat drinking water to reduce the risk of infectious disease through water consumption. Chlorination destroys all animal and microbial life in the water. It is a major factor in the reduction in the mortality rates associated with waterborne pathogen. Our reverse osmosis drinking water system removes chlorine from water.

Element/substance

Symbol/formula

Normally found in fresh water/ surface water/ ground water

Health based guideline by the WHO
Maximum limit

Aluminium Al 0.2 mg/l
Ammonia NH4 < 0.2 mg/l (up to 0.3 mg/l in anaerobic waters) No guideline
Antimony Sb < 4 μg/l 0.005 mg/l
Arsenic As 0.01 mg/l
Asbestos No guideline
Barium Ba 0.3 mg/l
Berillium Be < 1 μg/l No guideline
Boron B < 1 mg/l 0.3 mg/l
Cadmium Cd < 1 μg/l 0.003 mg/l
Chloride Cl 250 mg/l
Chromium Cr+3, Cr+6 < 2 μg/l 0.05 mg/l
Colour Not mentioned
Copper Cu 2 mg/l
Cyanide CN- 0.07 mg/l
Dissolved oxygen O2 No guideline
Fluoride F < 1.5 mg/l (up to 10) 1.5 mg/l
Hardness mg/l CaCO3 No guideline
Hydrogen sulfide H2S No guideline
Iron Fe 0.5 – 50 mg/l No guideline
Lead Pb 0.01 mg/l
Manganese Mn 0.5 mg/l
Mercury Hg < 0.5 μg/l 0.001 mg/l
Molybd enum Mb < 0,01 mg/l 0.07 mg/l
Nickel Ni < 0.02 mg/l 0.02 mg/l
Nitrate and nitrite NO3, NO2 50 mg/l total nitrogen
Turbidity Not mentioned
pH No guideline
Selenium Se < < 0.01 mg/l 0.01 mg/l
Silver Ag 5 – 50 μg/l No guideline
Sodium Na < 20 mg/l 200 mg/l
Sulfate SO4 500 mg/l
Inorganic tin Sn No guideline
TDS No guideline
Uranium U 1.4 mg/l
Zinc Zn 3 mg/l

Organic compounds

Group

Substance

Formula

Health based guideline by the WHO

Chlorinated alkanes Carbon tetrachloride C Cl4 2 μg/l
Dichloromethane C H2 Cl2 20 μg/l
1,1-Dichloroethane C2 H4 Cl2 No guideline
1,2-Dichloroethane Cl CH2 CH2 Cl 30 μg/l
1,1,1-Trichloroethane CH3 C Cl3 2000 μg/l
Chlorinated ethenes 1,1-Dichloroethene C2 H2 Cl2 30 μg/l
1,2-Dichloroethene C2 H2 Cl2 50 μg/l
Trichloroethene C2 H Cl3 70 μg/l

Tetrachloroethene

C2 Cl4

40 μg/l

Aromatic hydrocarbons

Benzene

C6 H6

10 μg/l

Toluene

C7 H8

700 μg/l

Xylenes

C8 H10

500 μg/l

Ethylbenzene

C8 H10

300 μg/l

Styrene

C8 H8

20 μg/l

Polynuclear Aromatic Hydrocarbons (PAHs)

C2 H3 N1 O5 P1 3

0.7 μg/l

Chlorinated benzenes

Monochlorobenzene (MCB)

C6 H5 Cl

300 μg/l

Dichlorobenzenes (DCBs)

1,2-Dichlorobenzene

C6 H4 Cl2

1000 μg/l

(1,2-DCB)

1,3-Dichlorobenzene (1,3-DCB)

C6 H4 Cl2

No guideline

1,4-Dichlorobenzene (1,4-DCB)

C6 H4 Cl2

300 μg/l

Trichlorobenzenes (TCBs) C6 H3 Cl3 20 μg/l
Miscellaneous organic constituents Di(2-ethylhexyl)adipate (DEHA) C22 H42 O4 80 μg/l
Di(2-ethylhexyl)phthalate (DEHP) C24 H38 O4
Acrylamide C3 H5 N O 0.5 μg/l
Epichlorohydrin (ECH) C3 H5 Cl O 0.4 μg/l
Hexachlorobutadiene (HCBD) C4 Cl6 0.6 μg/l
Ethylenediaminetetraacetic acid (EDTA) C10 H12 N2 O8

200 μg/l

Nitrilotriacetic acid (NTA) N(CH2COOH)3 200 μg/l
Organotins Dialkyltins R2 Sn X2 No guideline
Tributil oxide (TBTO) C24 H54 O Sn2

Pesticides

Substance Formula Health based guideline by the WHO
Alachlor C14 H20 Cl N O2 20 μg/l
Aldicarb C7 H14 N2 O4 S 10 μg/l
Aldrin and dieldrin C12 H8 Cl6/
C12 H8 Cl6 O
0.03 μg/l
Atrazine C8 H14 Cl N5 2 μg/l
Bentazone C10 H12 N2 O3 S 30 μg/l
Carbofuran C12 H15 N O3 5 μg/l
Chlordane C10 H6 Cl8 0.2 μg/l
Chlorotoluron C10 H13 Cl N2 O 30 μg/l
DDT C14 H9 Cl5 2 μg/l
1,2-Dibromo-3-chloropropane C3 H5 Br2 Cl 1 μg/l
2,4-Dichlorophenoxyacetic acid (2,4-D) C8 H6 Cl2 O3 30 μg/l
1,2-Dichloropropane C3 H6 Cl2 No guideline
1,3-Dichloropropane C3 H6 Cl2 20 μg/l
1,3-Dichloropropene CH3 CHClCH2 Cl No guideline
Ethylene dibromide (EDB) Br CH2 CH2 Br No guideline
Heptachlor and heptachlor epoxide C10 H5 Cl7 0.03 μg/l
Hexachlorobenzene (HCB) C10 H5 Cl7 O 1 μg/l
Isoproturon C12 H18 N2 O 9 μg/l
Lindane C6 H6 Cl6 2 μg/l
MCPA C9 H9 Cl O3 2 μg/l
Methoxychlor (C6H4OCH3)2CHCCl3 20 μg/l
Metolachlor C15 H22 Cl N O2 10 μg/l
Molinate C9 H17 N O S 6 μg/l
Pendimethalin C13 H19 O4 N3 20 μg/l
Pentachlorophenol (PCP) C6 H Cl5 O 9 μg/l
Permethrin C21 H20 Cl2 O3 20 μg/l
Propanil C9 H9 Cl2 N O 20 μg/l
Pyridate C19H23ClN2O2S 100 μg/l
Simazine C7 H12 Cl N5 2 μg/l
Trifluralin C13 H16 F3 N3 O4 20 μg/l
Chlorophenoxy
herbicides (excluding
2,4-D and MCPA)
2,4-DB C10 H10 Cl2 O3 90 μg/l
Dichlorprop C9 H8 Cl2 03 100 μg/l
Fenoprop C9H7Cl3O3 9 μg/l
MCPB C11 H13 Cl O3 No guideline
Mecoprop C10H11ClO3 10 μg/l
2,4,5-T C8 H5 Cl3 O3 9 μg/l

Disinfectants and disinfectant by-products

Group

Substance

Formula

Health based guideline by the WHO

Disinfectants Chloramines NHnCl(3-n),
where
n = 0,
1 or 2
3 mg/l
Chlorine Cl2 5 mg/l
Chlorine dioxide ClO2 No guideline
Iodine I2 No guideline
Disinfectant by-products Bromate Br O3- 25 μg/l
Chlorate Cl O3- No guideline
Chlorite Cl O2- 200 μg/l
Chlorophenols 2-Chlorophenol (2-CP) C6 H5 Cl O No guideline
2,4-Dichlorophenol (2,4-DCP) C6 H4 Cl2 O No guideline
2,4,6-Trichlorophenol (2,4,6-TCP) C6 H3 Cl3 O 200 μg/l
Formaldehyde HCHO 900 μg/l
MX (3-Chloro-4-dichloromethyl-5-hydroxy-2(5H)-furanone) C5 H3 Cl3 O3 No guideline
Trihalomethanes Bromoform C H Br3 100 μg/l
Dibromochloromethane CH Br2 Cl 100 μg/l
Bromodichloromethane CH Br Cl2 60 μg/l
Chloroform CH Cl3 200 μg/l
Chlorinated acetic acids Monochloroacetic acid C2 H3 Cl O2 No guideline
Dichloroacetic acid C2 H2 Cl2 O2 50 μg/l
Trichloroacetic acid C2 H Cl3 O2 100 μg/l
Chloral hydrate (trichloroacetaldehyde) C Cl3 CH(OH)2 10 μg/l
Chloroacetones C3 H5 O Cl No guideline
Halogenated acetonitriles Dichloroacetonitrile C2 H Cl2 N 90 μg/l
Dibromoacetonitrile 100 μg/l
Bromochloroacetonitrile CH Cl2 CN No guideline
Trichloroacetonitrile C2 Cl3 N 1 μg/l
Cyanogen chloride Cl CN 70 μg/l
Chloropicrin C Cl3 NO2 No guideline

 

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