The water treatment chemical database lists 124 chemicals and media with function, CAS number, systems, NSF/ANSI/CAN 60 status, AWWA and EN standard and 21 CFR 173.310 status, with NSF listing data as of 2026-10-20. Which chemical does a plant, cooling tower or boiler need, and which certification does it carry?
The 124 entries sit in 16 chemical families, from coagulants to filter media, plus a 17th group of 9 fluoridation and specialty wastewater chemicals; aluminium sulphate and polyaluminium chloride appear in US spelling. How each family works and is dosed is explained in the overview of water treatment chemicals.
Drinking water rows give the most common NSF/ANSI/CAN 60 maximum use level in mg/L as product with its range, such as 250 mg/L (31 to 795 mg/L) for ferric chloride. Filter media carry NSF/ANSI/CAN 61 process media status, and boiler amines carry 21 CFR 173.310 limits such as 10 ppm cyclohexylamine in steam.
Every row is checked against primary sources (NSF listings, AWWA, CEN, eCFR, PubChem and ECHA); listing data as of 2026-10-20. See our methodology and fact-checking process.
What Is in the Water Treatment Chemical Database?#
The water treatment chemical database is a table of every chemical and medium with its own page on this site: 124 entries, each dosed or specified to treat water in an industrial, municipal or utility system. Swimming pool, spa, household and emergency products are excluded.
Completeness is checked against 2 outside lists. Every chemical of the 49 ANSI/AWWA B-series standards has a row except sodium chloride (B200-22), potassium hydroxide (B511-23) and calcium chloride (B550-23), and the 36 in-use chemicals of the 47 US EPA Water Treatment Chemical Supply Chain Profiles (updated 2026-06-30) all have rows except potassium hydroxide and sodium chloride.
How are the 124 chemicals grouped?#
The 124 chemicals are grouped into 16 families plus a 17th group of 9 fluoridation and specialty wastewater chemicals. Two families, defoamers and antifoams and ion exchange resins, have no single-chemical rows, because their products are sold as formulations or resin grades. Table 1 compares the 17 groups by entries, members and main systems.
| # | Group | Entries | Members (short) | Main systems |
|---|---|---|---|---|
| 1 | coagulants for water treatment | 13 | alum, ferric and ferrous salts, PAC, ACH, sodium aluminate, polyDADMAC, polyamine, tannin, bentonite | drinking water, wastewater |
| 2 | flocculants for water treatment | 1 | polyacrylamide | drinking water, wastewater sludge |
| 3 | scale inhibitors | 11 | 5 phosphonates, 6 polymers | cooling, RO, boiler |
| 4 | phosphates in water treatment | 7 | ortho-, poly- and sodium phosphates, phosphoric acid | drinking water, boiler |
| 5 | corrosion inhibitors for water treatment | 7 | azoles, molybdate, nitrite, silicate, zinc | cooling, closed loop |
| 6 | oxygen scavengers for boiler water | 7 | sulfite, carbohydrazide, DEHA, hydrazine and others | boiler |
| 7 | neutralizing amines for condensate treatment | 7 | 6 neutralizing amines, octadecylamine | steam and condensate |
| 8 | biocides for water treatment | 11 | glutaraldehyde, isothiazolinone, DBNPA, THPS, quats, copper sulfate and others | cooling, RO, reservoirs |
| 9 | oxidants and oxidizing biocides | 17 | chlorine forms, ClO2 and precursors, chloramine, ozone, peroxygens, permanganates, bromine, oxygen | drinking water, wastewater, cooling |
| 10 | pH adjustment chemicals | 10 | caustic, lime, acids, soda ash, bicarbonate, Mg(OH)2, CO2, ammonia | all systems |
| 11 | dechlorination chemicals | 6 | bisulfite, metabisulfite, thiosulfates, ascorbic acid, SO2 | RO, wastewater, drinking water |
| 12 | chelating agents in water treatment | 6 | EDTA, citric acid, GLDA, MGDA, gluconate, NTA | boiler, cleaning |
| 13 | defoamers and antifoams | 0 | formulated products only | wastewater, cooling |
| 14 | descaling and chemical cleaning agents | 1 | sulfamic acid | heat exchangers, boilers, RO |
| 15 | ion exchange resins | 0 | resin types and grades | demineralization, softening |
| 16 | adsorbents and filter media | 11 | carbons, sands, greensand, MnO2, alumina, zeolite, calcite, DE, iron media | drinking water |
| 17a | water fluoridation chemicals | 3 | fluorosilicic acid, sodium fluorosilicate, sodium fluoride | drinking water |
| 17b | hydrogen sulfide and odor control chemicals | 2 | calcium nitrate, triazine | wastewater collection |
| 17c | heavy metal removal from wastewater | 3 | sodium sulfide, TMT, dithiocarbamate | industrial wastewater |
| 17d | chemical support for nitrogen removal | 1 | methanol | municipal and industrial wastewater |
| Total | 124 |
What does each database column mean?#
Each database row has 7 data columns, plus the 21 CFR 173.310 status for boiler steam. The 7 columns are listed below.
- Chemical: the name of the chemical's own page, with a synonym or use.
- Abbreviation or formula: such as PAC or FeCl3.
- CAS number: the primary number first, then salt, hydrate or isomer forms.
- Function: such as coagulant, scale inhibitor or dechlorination.
- Systems: such as drinking water, cooling, boiler, RO or wastewater.
- NSF/ANSI/CAN 60 status: the most common maximum use level (MUL) in mg/L as product, range and footnote code, NSF/ANSI/CAN 61 process media, or "not listed".
- AWWA / EN: the product standards; "none" means none was found.
The 21 CFR 173.310 column reads "listed", "listed" with its limit, or "not listed", and "not yet verified" marks a value still being checked.
The Complete Database: All 124 Water Treatment Chemicals by Family#
The complete database lists all 124 water treatment chemicals in 17 groups, each row linking to the chemical's own page. NSF/ANSI/CAN 60 values are product-specific maximum use levels in mg/L as product, totaled across all feed points, for drinking water only (NSF listings, 2026-10-20).
1. Coagulants (13)#
Coagulants are positively charged aluminum, iron and organic chemicals that destabilize turbidity and color at rapid mix; 13 are listed below.
| # | Chemical | Abbr. / formula | CAS (primary; also) | Function | Systems | NSF/ANSI/CAN 60 status | AWWA / EN | 21 CFR 173.310 |
|---|---|---|---|---|---|---|---|---|
| 1 | aluminum sulfate (alum) | Al2(SO4)3 | 10043-01-3 | coagulant; P precipitant; sludge conditioning | drinking water; municipal wastewater; industrial raw water | listed: 150 (25 to 500) [AL] | B403-24 / EN 878:2016 | not listed |
| 2 | ferric chloride | FeCl3 | 7705-08-0 (hexahydrate 10025-77-1) | coagulant; P and sulfide control; sludge conditioning | drinking water; wastewater; sewers | listed: 250 (31 to 795) | B407-24 / EN 888:2023 | not listed |
| 3 | ferric sulfate | Fe2(SO4)3 | 10028-22-5 | coagulant; P precipitant; sludge conditioning; H2S control | drinking water; wastewater | listed: 600 (20 to 650) | B406-20 / EN 890:2023 | not listed |
| 4 | aluminum chloride solution | AlCl3 | 7446-70-0 (hexahydrate 7784-13-6) | coagulant | drinking water | listed: 250 (70 to 250) [AL] | none / EN 17034:2018 | not listed |
| 5 | sodium aluminate | NaAlO2 | 1302-42-7 (also 11138-49-1) | coagulant; alkalinity source; softening aid | drinking water; lime softening; wastewater | listed: 89 and 105 (40 to 250) [AL] | B405-24 / EN 882:2016 | listed |
| 6 | ferrous chloride | FeCl2 | 7758-94-3 | sulfide control; coagulant; chlorite removal | sewers; wastewater; drinking water | listed: 300 (176 to 500) | none / none | not listed |
| 7 | ferrous sulfate | FeSO4 | 7720-78-7 (heptahydrate 7782-63-0) | coagulant after oxidation; reductant | drinking water; wastewater | listed: 150 (150 to 600) | B402-24 / EN 889:2023 | not listed |
| 8 | polyaluminum chloride (PAC) | PACl | 1327-41-9 | coagulant | drinking water; wastewater | listed: 250 (22 to 625) [AL] | B408-25 / EN 17034:2018 | not listed |
| 9 | aluminum chlorohydrate (ACH) | ACH | 12042-91-0 (1327-41-9 in trade) | coagulant | drinking water; membrane pretreatment; wastewater | listed: 250 (30 to 625) [AL] | supplied under B408-25 / EN 17034:2018 | not listed |
| 10 | polyDADMAC | pDADMAC | 26062-79-3 | coagulant; filter aid | drinking water; RO/UF pretreatment; wastewater | listed: 50 (1 to 250) | B451-23 / EN 1408 | not listed |
| 11 | polyamine (epi-DMA) coagulant | epi-DMA | 25988-97-0 (branched 42751-79-1) | coagulant; filter aid | drinking water; wastewater | listed: 10 (1 to 46) [PY] | B452-20 / EN 1409 | not listed |
| 12 | tannin (quebracho extract) | plant extract | not yet verified | coagulant; boiler oxygen scavenger and sludge conditioner | drinking water; low-pressure boilers | listed: 1.2 to 1.5 (coagulation products) | none / none | listed |
| 13 | bentonite (coagulant aid) | montmorillonite clay | 1302-78-9 | floc weighting; filtration aid | drinking water | listed: 200 or 250 (coagulation) | none / none | not listed |
2. Flocculants (1)#
Flocculants are high-molecular-weight polymers that bridge particles into floc; 1 is listed, polyacrylamide in anionic, nonionic and cationic grades.
| # | Chemical | Abbr. / formula | CAS (primary; also) | Function | Systems | NSF/ANSI/CAN 60 status | AWWA / EN | 21 CFR 173.310 |
|---|---|---|---|---|---|---|---|---|
| 14 | polyacrylamide (PAM) | PAM | 9003-05-8 (nonionic homopolymer; copolymers carry their own CAS) | flocculant; coagulant and filter aid; sludge conditioning | drinking water; wastewater thickening and dewatering | listed: 1 (about 0.2 to 160) [PC] | B453-24 / EN 1407:2023, EN 1410:2023 | listed only as acrylamide-sodium acrylate resin |
3. Scale inhibitors (11)#
Scale inhibitors are phosphonates and carboxylate polymers that prevent carbonate, sulfate and phosphate scale at low doses; 11 are listed below.
| # | Chemical | Abbr. / formula | CAS (primary; also) | Function | Systems | NSF/ANSI/CAN 60 status | AWWA / EN | 21 CFR 173.310 |
|---|---|---|---|---|---|---|---|---|
| 15 | HEDP (etidronic acid) | HEDP | 2809-21-4 (tetrasodium salt 3794-83-0) | scale and corrosion inhibitor; sequestrant; RO antiscalant | cooling; RO; boiler; closed loop | listed as RO antiscalant: 20 (0.8 to 80) | none / EN 15040:2014 | listed, no numeric limit |
| 16 | ATMP (amino trimethylene phosphonic acid) | ATMP | 6419-19-8 (pentasodium salt 2235-43-0) | scale inhibitor; RO antiscalant; chelant | cooling; RO | listed as RO antiscalant: 20 (4 to 100) | none / EN 15040:2014 | not listed |
| 17 | PBTC (phosphonobutane tricarboxylic acid) | PBTC | 37971-36-1 (sodium salt 40372-66-5) | scale and corrosion inhibitor; zinc stabilizer; RO antiscalant | cooling; RO | listed as RO antiscalant: 20 (5 to 20) | none / EN 15040:2014 | not listed |
| 18 | DTPMP | DTPMP | 15827-60-8 (sodium salt 22042-96-2) | scale inhibitor (carbonate, sulfate, barium); RO antiscalant; chelant | RO; cooling; boiler | listed: 20 (3 to 20) | none / EN 15040:2014 | not listed |
| 19 | HPAA (hydroxyphosphonoacetic acid) | HPAA | 23783-26-8 | carbon-steel corrosion inhibitor; secondary scale inhibitor | cooling; closed loop | not listed | none / outside EN 15040:2014 scope | not listed |
| 20 | polyacrylic acid and sodium polyacrylate | PAA / PAAS | 9003-01-4 (sodium salt 9003-04-7) | scale inhibitor; dispersant; antiscalant | cooling; boiler; RO | listed: 20 (2.5 to 100); sodium polyacrylate 1 to 125 | none / EN 15039:2014 | sodium polyacrylate listed |
| 21 | polymaleic acid (HPMA) | HPMA | 26099-09-2 | scale inhibitor; antiscalant; dispersant | cooling; boiler; RO; thermal desalination | listed: 20 (3 to 20) | none / EN 15039:2014 | listed: 1 ppm in feedwater |
| 22 | AA/AMPS copolymer | AA/AMPS | 40623-75-4 (sodium salt 37350-42-8) | scale inhibitor; dispersant | cooling; boiler | no dedicated category (blends product-specific) | none / EN 15039:2014 (membrane use) | listed: 20 ppm active in feedwater |
| 23 | phosphinocarboxylic acid (PCA) | PCA | 71050-62-9 | scale inhibitor; dispersant | cooling; boiler | not yet verified | none / none | listed: 1.5 ppm in feedwater |
| 24 | polyaspartic acid (PASP) | PASP | 25608-40-6 (sodium salt 181828-06-8) | scale inhibitor; dispersant | cooling | not listed (no category) | none / none | not listed |
| 25 | polyepoxysuccinic acid (PESA) | PESA | 51274-37-4 | scale inhibitor | cooling; RO | not listed (no category) | none / none | not listed |
4. Phosphates (7)#
Phosphates are ortho-, poly- and sodium phosphate salts for corrosion control, sequestering and boiler treatment; 7 are listed below.
| # | Chemical | Abbr. / formula | CAS (primary; also) | Function | Systems | NSF/ANSI/CAN 60 status | AWWA / EN | 21 CFR 173.310 |
|---|---|---|---|---|---|---|---|---|
| 26 | sodium hexametaphosphate (SHMP) | SHMP | 68915-31-1 (cyclic hexamer 10124-56-8) | sequestrant (Fe, Mn, Ca, Mg); threshold scale inhibitor | drinking water; cooling; boiler; RO | listed: 10 to 60 | B502-23 / EN 1212 | listed |
| 27 | trisodium phosphate (TSP) | Na3PO4 | 7601-54-9 (dodecahydrate 10101-89-0) | boiler internal treatment; alkalinity source | boiler; drinking water | listed: 17 (12 to 42) | none / EN 1200 | listed |
| 28 | zinc orthophosphate | Zn3(PO4)2 | 7779-90-0 | corrosion inhibitor (lead, copper, iron) | drinking water; cooling | listed: 6 to 40 [ZN] | B506-25 / none | not listed |
| 29 | phosphoric acid | H3PO4 | 7664-38-2 | orthophosphate corrosion inhibitor; pH adjuster | drinking water; RO/NF cleaning | listed: 12 to 13 (commodity grades) | B507-23 / EN 974 | not listed |
| 30 | monosodium phosphate (MSP) | NaH2PO4 | 7558-80-7 | orthophosphate source; boiler pH reduction | drinking water; boiler | listed: 13 (up to 62) | B504-24 / EN 1198 | listed |
| 31 | disodium phosphate | Na2HPO4 | 7558-79-4 | boiler internal treatment | boiler; drinking water | listed: 15 | B505-24 / EN 1199 | listed |
| 32 | sodium tripolyphosphate (STPP) | STPP | 7758-29-4 | sequestrant; scale and corrosion control | drinking water; boiler; RO/NF cleaning | listed: 12 to 13 | B503-23 / EN 1210 | listed |
5. Corrosion inhibitors (7)#
Corrosion inhibitors are azoles, molybdate, nitrite, silicate and zinc that protect copper and steel in cooling and closed loops; 7 are listed below.
| # | Chemical | Abbr. / formula | CAS (primary; also) | Function | Systems | NSF/ANSI/CAN 60 status | AWWA / EN | 21 CFR 173.310 |
|---|---|---|---|---|---|---|---|---|
| 33 | benzotriazole (BZT) | BZT | 95-14-7 | copper and yellow-metal corrosion inhibitor | cooling | not listed (no azole category) | none / none | not listed |
| 34 | sodium molybdate | Na2MoO4 | 7631-95-0 (dihydrate 10102-40-6) | anodic corrosion inhibitor; tracer | closed loop | not listed (no category) | none / none | not listed |
| 35 | sodium nitrite | NaNO2 | 7632-00-0 | anodic corrosion inhibitor | closed loop; chilled water | not listed (no category) | none / none | not listed |
| 36 | tolyltriazole (TTA) | TTA | 29385-43-1 | copper and yellow-metal corrosion inhibitor | cooling; closed loop | not listed (no azole category) | none / none | not listed |
| 37 | sodium silicate | Na2O·nSiO2 | 1344-09-8 (metasilicate 6834-92-0) | corrosion inhibitor; sequestrant; coagulant aid | drinking water; closed loop | listed: 42 (10 to 353) | B404-22 / EN 1209 | listed |
| 38 | zinc salts (zinc sulfate, zinc chloride) | ZnSO4 / ZnCl2 | 7733-02-0 (zinc chloride 7646-85-7) | cathodic corrosion inhibitor | cooling; drinking water | listed: 5 to 15 [ZN] | none / none | not listed |
| 39 | mercaptobenzothiazole (MBT) | MBT | 149-30-4 (sodium salt 2492-26-4) | copper corrosion inhibitor | cooling; closed loop | not listed (no category) | none / none | not listed |
6. Oxygen scavengers (7)#
Oxygen scavengers are reducing chemicals, such as sodium sulfite and DEHA, that remove dissolved oxygen from boiler feedwater; 7 are listed below.
| # | Chemical | Abbr. / formula | CAS (primary; also) | Function | Systems | NSF/ANSI/CAN 60 status | AWWA / EN | 21 CFR 173.310 |
|---|---|---|---|---|---|---|---|---|
| 40 | carbohydrazide | CHZ | 497-18-7 | oxygen scavenger; metal passivator | medium- and high-pressure boilers; lay-up | not listed (boiler use outside NSF 60 scope) | none / none | not listed |
| 41 | sodium sulfite | Na2SO3 | 7757-83-7 | oxygen scavenger | boilers below 1,000 psig (69 bar); closed loop | not listed (boiler use outside NSF 60 scope) | none / EN 12124:2022 | listed |
| 42 | DEHA (diethylhydroxylamine) | DEHA | 3710-84-7 | oxygen scavenger; passivator; condensate protection | boiler and condensate; closed loop | not listed (boiler use outside NSF 60 scope) | none / none | not listed |
| 43 | hydrazine | N2H4 | 302-01-2 (hydrate 7803-57-8) | oxygen scavenger; AVT reducing agent | boilers at 1,000 psig (69 bar) and above; lay-up | not listed (boiler use outside NSF 60 scope) | none / none | zero in steam |
| 44 | sodium erythorbate | C6H7NaO6 | 6381-77-7 (erythorbic acid 89-65-6) | oxygen scavenger; passivator | low- and medium-pressure boilers | not listed (boiler use outside NSF 60 scope) | none / none | not listed |
| 45 | hydroquinone | HQ | 123-31-9 | oxygen scavenger; scavenger catalyst | boiler feedwater; lay-up | not listed (boiler use outside NSF 60 scope) | none / none | not listed |
| 46 | MEKO (methyl ethyl ketoxime) | MEKO | 96-29-7 | volatile oxygen scavenger | boiler feedwater | not listed (boiler use outside NSF 60 scope) | none / none | not listed |
7. Neutralizing and filming amines (7)#
Neutralizing and filming amines are volatile amines that raise condensate pH or film steel; 7 are listed below.
| # | Chemical | Abbr. / formula | CAS (primary; also) | Function | Systems | NSF/ANSI/CAN 60 status | AWWA / EN | 21 CFR 173.310 |
|---|---|---|---|---|---|---|---|---|
| 47 | morpholine | MOR | 110-91-8 | neutralizing amine | steam and condensate; utility cycles | not listed (not a drinking water chemical) | none / none | 10 ppm in steam |
| 48 | cyclohexylamine | CHA | 108-91-8 | neutralizing amine | steam and condensate | not listed (not a drinking water chemical) | none / none | 10 ppm in steam |
| 49 | DEAE (diethylaminoethanol) | DEAE | 100-37-8 | neutralizing amine | steam and condensate | not listed (not a drinking water chemical) | none / none | 15 ppm in steam |
| 50 | MOPA (methoxypropylamine) | MOPA | 5332-73-0 | neutralizing amine | steam and condensate; HRSG | not listed (not a drinking water chemical) | none / none | not listed |
| 51 | AMP (2-amino-2-methyl-1-propanol) | AMP | 124-68-5 | neutralizing amine | steam and condensate | not listed (not a drinking water chemical) | none / none | not listed |
| 52 | octadecylamine (ODA) | ODA | 124-30-1 | filming amine | steam and condensate; lay-up | not listed | none / none | 3 ppm in steam |
| 53 | ethanolamine (ETA/MEA) | ETA | 141-43-5 | alkalizing amine for steam-water cycles | utility, HRSG and PWR secondary cycles | not listed (not a drinking water chemical) | none / none | not listed |
8. Non-oxidizing biocides and algaecides (11)#
Non-oxidizing biocides and algaecides are organic and copper actives, such as glutaraldehyde and DBNPA, used where oxidizers fail; 11 are listed below.
| # | Chemical | Abbr. / formula | CAS (primary; also) | Function | Systems | NSF/ANSI/CAN 60 status | AWWA / EN | 21 CFR 173.310 |
|---|---|---|---|---|---|---|---|---|
| 54 | glutaraldehyde | C5H8O2 | 111-30-8 | non-oxidizing biocide | cooling; closed loop; industrial RO/UF; wastewater | no listing found (algicide function) | none / none | not listed |
| 55 | isothiazolinone (CMIT/MIT) | CMIT/MIT | 55965-84-9 (CMIT 26172-55-4; MIT 2682-20-4) | non-oxidizing biocide | cooling; RO membranes | no CMIT/MIT-specific listing verified | none / none | not listed |
| 56 | DBNPA | DBNPA | 10222-01-2 | non-oxidizing biocide | cooling; closed loop; RO/NF | only formulated RO membrane biocides | none / none | not listed |
| 57 | THPS (tetrakis(hydroxymethyl)phosphonium sulfate) | THPS | 55566-30-8 | non-oxidizing biocide | cooling; offshore RO/NF | not yet verified | none / none | not listed |
| 58 | quaternary ammonium compounds (ADBAC, DDAC) | QAC | ADBAC C12-16 68424-85-1; DDAC 7173-51-5 | non-oxidizing biocide | cooling; once-through cooling | not yet verified | none / none | not listed |
| 59 | bronopol | C3H6BrNO4 | 52-51-7 | non-oxidizing biocide | cooling; air washers | not yet verified | none / none | not listed |
| 60 | polyquaternium algaecide (WSCP) | WSCP | 31512-74-0 | algaecide; bactericide; molluscicide | cooling; drinking water intakes | listed: 0.5 (2 to 5 for up to 21 days at start) | none / none | not listed |
| 61 | TTPC (tributyl tetradecyl phosphonium chloride) | TTPC | 81741-28-8 | non-oxidizing biocide; biodispersant | cooling | not yet verified | none / none | not listed |
| 62 | copper sulfate (reservoir algaecide) | CuSO4·5H2O | 7758-99-8 (anhydrous 7758-98-7) | algaecide | drinking water source reservoirs | listed: 4 (1 to 20) [CP] | B602 / none | not listed |
| 63 | dodecylguanidine hydrochloride (DGH) | DGH | 13590-97-1 | non-oxidizing biocide | cooling; closed loop | not yet verified | none / none | not listed |
| 64 | methylene bis(thiocyanate) | C3H2N2S2 | 6317-18-6 | non-oxidizing biocide | cooling | not yet verified | none / none | not listed |
9. Oxidants and oxidizing biocides (17)#
Oxidants and oxidizing biocides are chlorine and bromine compounds, chlorine dioxide, ozone, peroxygens and permanganates; 17 are listed below.
| # | Chemical | Abbr. / formula | CAS (primary; also) | Function | Systems | NSF/ANSI/CAN 60 status | AWWA / EN | 21 CFR 173.310 |
|---|---|---|---|---|---|---|---|---|
| 65 | sodium hypochlorite | NaOCl | 7681-52-9 | disinfectant; oxidizing biocide; oxidant | drinking water; wastewater; cooling; RO and UF cleaning | listed: 84 (12.5 % products; most 40 to 210) | B300-24 / EN 901:2024 | not listed |
| 66 | chlorine dioxide | ClO2 | 10049-04-4 | primary disinfectant; oxidant; oxidizing biocide | drinking water; building water; cooling; wastewater | precursors listed (sodium chlorite, sodium chlorate) | precursor B303-24 / EN 12671:2016 | not listed |
| 67 | monochloramine | NH2Cl | 10599-90-3 | secondary (residual) disinfectant | drinking water; building water | precursors listed (ammonia sources, chlorine, hypochlorite) | precursor standards only | not listed |
| 68 | ozone | O3 | 10028-15-6 | disinfectant; oxidant; AOP | drinking water; wastewater | no listing returned (generated on site) | none / EN 1278:2026 | not listed |
| 69 | peracetic acid (PAA) | PAA | 79-21-0 | wastewater disinfectant; biocide | wastewater; cooling; RO/NF sanitization | no listing returned | none / none | not listed |
| 70 | potassium permanganate | KMnO4 | 7722-64-7 | oxidant (Fe, Mn, H2S, taste and odor, color) | drinking water; wastewater | listed: 50 (solid grades) [MN] | B603 / EN 12672 | not listed |
| 71 | calcium hypochlorite | Ca(OCl)2 | 7778-54-3 | disinfectant; oxidant | small drinking water systems; wastewater | listed: 15 | B300-24 / EN 900 | not listed |
| 72 | chlorine gas | Cl2 | 7782-50-5 | disinfectant; oxidant | drinking water; wastewater; once-through cooling | listed: 30 | B301-24 / EN 937:2016 | not listed |
| 73 | hydrogen peroxide | H2O2 | 7722-84-1 | oxidant; AOP radical source; sulfide oxidant | drinking water; potable reuse; wastewater; RO/NF | listed: strength-specific (50 % grades 2.1 or 16) [HP] | none / EN 902 | not listed |
| 74 | sodium chlorite | NaClO2 | 7758-19-2 | chlorine dioxide precursor | drinking water; cooling; wastewater | listed: 28 (25 % solutions), 22 (31 %) | B303-24 / EN 938:2016 | not listed |
| 75 | ammonium sulfate (chloramination) | (NH4)2SO4 | 7783-20-2 | ammonia source for chloramination | drinking water; RO | listed: 60 (40 % solutions; 5 to 184) | B302-23 / EN 12123:2022 | not listed |
| 76 | sodium permanganate | NaMnO4 | 10101-50-5 | oxidant | drinking water | listed: 176 (20 %), 88 (40 %) [MN] | B603 / EN 15482 | not listed |
| 77 | oxygen (LOX) | O2 | 7782-44-7 | ozone feed gas; oxygenation | drinking water; wastewater | listed: MUL NA (ozone generators) | B304-21 / EN 12876 | not yet verified |
| 78 | trichloroisocyanuric acid (TCCA) tablets | TCCA | 87-90-1 | slow-release chlorine donor | small drinking water systems; small wastewater plants; cooling | listed: 30 | none / none | not listed |
| 79 | BCDMH (bromochlorodimethylhydantoin) | BCDMH | 16079-88-2 | bromine-releasing biocide | cooling; closed loop; evaporative desalination | listed: 3 to 15 | none / none | not listed |
| 80 | sodium bromide (activated bromine) | NaBr | 7647-15-6 | bromine biocide precursor | cooling | no listing found | none / none | not listed |
| 81 | sodium chlorate | NaClO3 | 7775-09-9 | chlorine dioxide precursor | drinking water | listed: 8 to 18 | none / none | not listed |
10. pH adjusters (10)#
pH adjusters are acids, alkalis and carbon dioxide that set pH and alkalinity; 10 are listed below.
| # | Chemical | Abbr. / formula | CAS (primary; also) | Function | Systems | NSF/ANSI/CAN 60 status | AWWA / EN | 21 CFR 173.310 |
|---|---|---|---|---|---|---|---|---|
| 82 | sodium hydroxide (caustic soda) | NaOH | 1310-73-2 | pH and alkalinity adjuster; resin regenerant | drinking water; wastewater; ion exchange; boiler; RO/NF cleaning | listed: 100 (strength-specific) | B501-25 / EN 896 | listed |
| 83 | hydrated lime (calcium hydroxide) | Ca(OH)2 | 1305-62-0 | pH adjuster; softening; alkalinity and calcium source | drinking water; wastewater; cooling makeup | listed: 650 (dry; 40 to 4,961) | B202-25 / EN 12518 | not listed |
| 84 | sulfuric acid | H2SO4 | 7664-93-9 | pH and alkalinity reduction; resin regenerant | cooling; drinking water; ion exchange; wastewater | listed: 50 (93 to 98 % grades) | none / EN 899:2022 | not listed |
| 85 | soda ash (sodium carbonate) | Na2CO3 | 497-19-8 | alkalinity and pH adjuster; softening | drinking water; wastewater; boiler pretreatment | listed: 150 (dry grades 100 to 200) | B201 / EN 897 | listed |
| 86 | sodium bicarbonate | NaHCO3 | 144-55-8 | alkalinity source; buffer | drinking water; wastewater | listed: 200 (100 to 1,000) | none / EN 898 | not listed |
| 87 | magnesium hydroxide | Mg(OH)2 | 1309-42-8 | self-buffering alkali; H2S and odor control | industrial wastewater; collection systems; hot process softening | listed: 300 (150 to 300) | none / none | not listed |
| 88 | carbon dioxide (CO2) | CO2 | 124-38-9 | pH reduction; recarbonation | drinking water; cooling; wastewater | listed: 100 (25 to 200) | B510 / EN 936 | not listed |
| 89 | hydrochloric acid | HCl | 7647-01-0 | pH reduction; resin regenerant; descaler | drinking water; cooling; ion exchange; wastewater; RO/NF cleaning | listed: 40 (strength-specific) | none / EN 939:2016 | not listed |
| 90 | quicklime (calcium oxide) | CaO | 1305-78-8 | pH adjuster and softening agent after slaking | drinking water; wastewater | listed: 500 (326 to 500) | B202-25 / EN 12518 | not listed |
| 91 | ammonia (aqueous and anhydrous) | NH3 | 7664-41-7 (ammonium hydroxide 1336-21-6) | chloramination ammonia source; AVT pH control | drinking water; boiler | listed: anhydrous 5; aqua 10 (1 to 33) | B305-22, B306-22 / EN 12126:2022, EN 12122:2024 | not listed |
11. Dechlorination chemicals (6)#
Dechlorination chemicals are sulfur and ascorbate reducing agents that remove chlorine before RO or discharge; 6 are listed below.
| # | Chemical | Abbr. / formula | CAS (primary; also) | Function | Systems | NSF/ANSI/CAN 60 status | AWWA / EN | 21 CFR 173.310 |
|---|---|---|---|---|---|---|---|---|
| 92 | sodium bisulfite | NaHSO3 | 7631-90-5 | dechlorination; oxygen scavenger | wastewater; RO; drinking water; cooling | listed: 46 (8 to 160) [SF] | none / EN 12120:2022 | not listed |
| 93 | sodium metabisulfite (SMBS) | Na2S2O5 | 7681-57-4 | dechlorination; RO biostatic | RO; wastewater; drinking water | listed: 15 (10 to 50) [SF] | B601-25 / EN 12121:2022 | listed |
| 94 | sodium thiosulfate | Na2S2O3 | 7772-98-7 (pentahydrate 10102-17-7) | dechlorination; ozone reduction | drinking water; wastewater | listed as miscellaneous chemical: 50 (30 % solutions) | C655-25 / EN 12125:2022 | not listed |
| 95 | ascorbic acid (vitamin C) dechlorination | C6H8O6 | 50-81-7 (sodium ascorbate 134-03-2) | dechlorination | drinking water | listed: 12 | C655-25 / none | not listed |
| 96 | sulfur dioxide | SO2 | 7446-09-5 | dechlorination (sulfonation) | wastewater | listed: 10 | B512-23 / none | not listed |
| 97 | calcium thiosulfate | CaS2O3 | 10124-41-1 | dechlorination; ozone reduction | drinking water; wastewater | listed: 50 | none / none | not listed |
12. Chelants (6)#
Chelants are aminocarboxylates and organic acids that bind hardness and iron in boilers and cleaning; 6 are listed below.
| # | Chemical | Abbr. / formula | CAS (primary; also) | Function | Systems | NSF/ANSI/CAN 60 status | AWWA / EN | 21 CFR 173.310 |
|---|---|---|---|---|---|---|---|---|
| 98 | EDTA | EDTA / Na4EDTA | 60-00-4 (Na4EDTA 64-02-8) | chelant; boiler chelant program; chemical cleaning | boiler; RO/NF cleaning; industrial wastewater | no category (proprietary cleaners only) | none / none | tetrasodium EDTA listed |
| 99 | citric acid | C6H8O7 | 77-92-9 | membrane cleaner; descaler | RO/NF/UF cleaning; boiler cleaning; wells | listed as membrane cleaner: MUL NA | none / none | not listed |
| 100 | GLDA | GLDA | 51981-21-6 | chelant; descaling chelant | chemical cleaning | not listed (no category) | none / none | not listed |
| 101 | MGDA | MGDA | 164462-16-2 | chelant; cleaning builder | boiler cleaning; CIP | not listed (no category) | none / none | not listed |
| 102 | sodium gluconate | C6H11NaO7 | 527-07-1 | chelant at high alkalinity | alkaline cleaning; cooling (research) | not listed (no category) | none / none | not listed |
| 103 | NTA (nitrilotriacetic acid) | NTA | 139-13-9 (Na3NTA 5064-31-3) | boiler chelant (historic) | boiler | not listed (no category) | none / none | Na3NTA: 5 ppm in feedwater |
13. Defoamers and antifoams (0 entity pages)#
Defoamers and antifoams are silicone and non-silicone formulations with no single-chemical row; they are compared on their family page (Table 1, row 13).
14. Descaling and cleaning agents (1)#
Descaling and cleaning agents are acids and inhibited blends that remove scale; 1 is listed, sulfamic acid, while citric acid and EDTA stay in their families.
| # | Chemical | Abbr. / formula | CAS (primary; also) | Function | Systems | NSF/ANSI/CAN 60 status | AWWA / EN | 21 CFR 173.310 |
|---|---|---|---|---|---|---|---|---|
| 104 | sulfamic acid | NH2SO3H | 5329-14-6 | descaler; RO membrane cleaner | heat exchangers; boilers; RO/NF | not listed (no category) | none / EN 17841:2024 (membrane use) | not listed |
15. Ion exchange resins (0 entity pages)#
Ion exchange resins are cation and anion beads sold by type and grade, with no single-chemical row; they are compared on their family page (Table 1, row 15).
16. Adsorbents and filter media (11)#
Adsorbents and filter media are carbons, sands, minerals and coated media; 11 are listed below, 10 as NSF/ANSI/CAN 61 process media.
| # | Chemical | Abbr. / formula | CAS (primary; also) | Function | Systems | NSF/ANSI/CAN 60 status | AWWA / EN | 21 CFR 173.310 |
|---|---|---|---|---|---|---|---|---|
| 105 | powdered activated carbon (PAC) | PAC (carbon) | 64365-11-3 | adsorbent (dosed) | drinking water (taste and odor, SOCs, PFAS) | NSF/ANSI/CAN 61 process media: 100, 250, 590 or 750 | B600-24 / EN 12903 | not listed |
| 106 | zeolite (clinoptilolite) | clinoptilolite | 12173-10-3 (zeolites 1318-02-1) | filter medium; ammonium ion exchanger | municipal wastewater; drinking water | NSF/ANSI/CAN 61 process media | none / none | not listed |
| 107 | granular activated carbon (GAC) | GAC | 64365-11-3 | adsorbent; filter-adsorber | drinking water (DBP precursors, taste and odor, PFAS); industrial | NSF/ANSI/CAN 61 process media | B604-18, B605-18 / EN 12915-1 | not listed |
| 108 | anthracite filter media | C (mainly) | 8029-10-5 | filter medium (upper layer) | drinking water filters; RO pretreatment | NSF/ANSI/CAN 61 process media | B100-25 / EN 12909 | not listed |
| 109 | manganese greensand | MGS | not yet verified | catalytic oxidation of Fe, Mn and H2S | groundwater drinking water | NSF/ANSI/CAN 61 process media | B102-26 / EN 12911 | not listed |
| 110 | manganese dioxide filter media | MnO2 | 1313-13-9 | catalytic oxidation of Fe, Mn and H2S | groundwater drinking water | NSF/ANSI/CAN 61 process media | B103-25 / EN 13752 | not listed |
| 111 | calcite (calcium carbonate) media | CaCO3 | 471-34-1 (calcite 13397-26-7) | neutralizing and remineralizing medium | drinking water pH correction; desalination remineralization | NSF/ANSI/CAN 60 listed (media exception): 650 | none / EN 1018:2026 | not listed |
| 112 | silica filter sand and garnet | SiO2; garnet | 14808-60-7 (quartz); 12178-41-5 (garnet group) | filter medium | drinking water; cooling side-stream; RO pretreatment | NSF/ANSI/CAN 61 process media | B100-25 / EN 12904 | not listed |
| 113 | activated alumina | Al2O3 | 1344-28-1 | adsorbent for fluoride, arsenate, selenite | drinking water | NSF/ANSI/CAN 61 process media | none / EN 13753 | not listed |
| 114 | diatomaceous earth (precoat filter media) | DE | 61790-53-2 | precoat filter medium | drinking water (DE filtration) | NSF/ANSI/CAN 61 process media | B101-22 / none | not listed |
| 115 | granular ferric hydroxide and ferric oxide media (GFH/GFO) | GFH | 1309-33-7 (FeO(OH) 20344-49-4) | adsorbent for arsenic and phosphate | drinking water (arsenic) | NSF/ANSI/CAN 61 process media | none / none | not listed |
17. Fluoridation and specialty wastewater chemicals (9)#
Fluoridation and specialty wastewater chemicals are 3 fluoride sources and 6 chemicals for sulfide, metal and nitrogen control; 9 are listed below.
| # | Chemical | Abbr. / formula | CAS (primary; also) | Function | Systems | NSF/ANSI/CAN 60 status | AWWA / EN | 21 CFR 173.310 |
|---|---|---|---|---|---|---|---|---|
| 116 | fluorosilicic acid (FSA) | H2SiF6 | 16961-83-4 | fluoridation agent | community water fluoridation | listed: 5 | B703-24 / EN 12175:2022 | not listed |
| 117 | sodium fluorosilicate | Na2SiF6 | 16893-85-9 | fluoridation agent (dry) | community water fluoridation | listed as sodium silicofluoride: 1.2 | B702-24 / EN 12174:2022 | not listed |
| 118 | sodium fluoride for water fluoridation | NaF | 7681-49-4 | fluoridation agent (saturators) | small drinking water systems | listed: 2.2 | B701-24 / EN 12173 | not listed |
| 119 | calcium nitrate (septicity and H2S control) | Ca(NO3)2 | 10124-37-5 (tetrahydrate 13477-34-4) | sulfide prevention; septicity and odor control | wastewater collection; headworks | not listed (no category) | none / none | not listed |
| 120 | triazine H2S scavenger | HHT | 4719-04-4 | H2S scavenger | produced and sour water; industrial wastewater | not listed (no category) | none / none | not listed |
| 121 | sodium sulfide and sodium hydrosulfide | Na2S / NaHS | 1313-82-2 (NaHS 16721-80-5) | heavy metal precipitant | industrial wastewater | not yet verified | none / none | not listed |
| 122 | TMT (trimercapto-s-triazine) | TMT | 17766-26-6 | heavy metal precipitant | industrial wastewater; scrubber water | not yet verified | none / none | not listed |
| 123 | dithiocarbamate metal precipitants | SDDC | 128-04-1 (DDTC 148-18-5) | heavy metal precipitant (chelated metals) | industrial wastewater | not yet verified | none / none | not listed |
| 124 | methanol (denitrification carbon source) | CH3OH | 67-56-1 | carbon source for denitrification | municipal and industrial wastewater | not listed (no category) | none / none | not listed |
How to Read NSF/ANSI/CAN 60 Status in the Database#
NSF/ANSI/CAN 60 status in the database means the chemical is certified as a drinking water additive with a maximum use level (MUL), the highest dose in mg/L as product, totaled across all application points. MULs are product-specific, so each cell gives the most common value and the range; 12.5 % sodium hypochlorite is most often listed at 84 mg/L.
Footnote codes cap the finished water: [AL] aluminum 2 mg/L, [ZN] zinc 2.0 mg/L, [MN] manganese 0.05 mg/L, [CP] copper 1.3 mg/L, [SF] residual sulfite 0.1 mg/L and [HP] chlorine residual 4 mg/L after peroxide; [PC] and [PY] mark compliance with 40 CFR 141.111. NSF/ANSI/CAN 60 is adopted by 48 of 50 US states (NSF, 2019), and listing checks are explained on the NSF/ANSI/CAN 60 page.
Which database entries are NSF/ANSI/CAN 61 process media instead?#
10 of the 11 adsorbents and filter media in the database are certified under NSF/ANSI/CAN 61 as process media, not under NSF/ANSI/CAN 60. NSF/ANSI/CAN 61 covers components and indirect additives, while NSF/ANSI/CAN 60 covers chemicals added directly. Calcium carbonate is the exception, listed under NSF/ANSI/CAN 60 at 650 mg/L as product for most listings, and powdered activated carbon carries NSF/ANSI/CAN 61 levels of 100, 250, 590 or 750 mg/L.
Why do boiler and cooling chemicals show "not listed"?#
Boiler and cooling chemicals show "not listed" because NSF/ANSI/CAN 60 covers chemicals added to drinking water, and oxygen scavengers, amines and most cooling corrosion inhibitors have no drinking water role. For boiler chemicals, the relevant listing is 21 CFR 173.310, covered in the standards section below.
CAS Numbers, Names and Abbreviations of Water Treatment Chemicals#
CAS numbers in the database list the primary registry number first and the salt, hydrate or isomer forms after it. Ferric chloride reads 7705-08-0 with the hexahydrate 10025-77-1, and HEDP reads 2809-21-4 with the tetrasodium salt 3794-83-0. Polyacrylamide carries 9003-05-8 for the nonionic homopolymer; copolymer grades carry their own numbers. Synonyms stand next to each water treatment chemical name.
Which abbreviations name two different chemicals?#
Four abbreviations name two different water treatment chemicals: PAC, PAA, MBT and AA. MBT stands only for mercaptobenzothiazole here, and methylene bis(thiocyanate) is written in full. ATMP is searched as "ATMP phosphonate", because ATMP alone is also a pharmaceutical acronym. Table 3 lists both meanings with their row numbers.
| Abbreviation | Chemical 1 (row) | Chemical 2 (row) | How this page writes it |
|---|---|---|---|
| PAC | polyaluminum chloride (8) | powdered activated carbon (105) | "PAC coagulant" / "powdered activated carbon (PAC)" |
| PAA | peracetic acid (69) | polyacrylic acid (20) | "peracetic acid (PAA)" / "polyacrylic acid (PAA/PAAS)" |
| MBT | mercaptobenzothiazole (39) | methylene bis(thiocyanate) (64) | MBT only for mercaptobenzothiazole |
| AA | acrylic acid in AA/AMPS (22) | activated alumina (113); ascorbic acid (95) | never "AA" alone |
Which CAS numbers are most often confused?#
Four identifier pairs are often swapped, and each swap names a different chemical. The 4 pairs are listed below.
- Aluminum sulfate: 10043-01-3; the look-alike 10043-67-1 is potassium alum.
- Fluorosilicic acid: 16961-83-4; the look-alike 7664-39-3 is hydrofluoric acid.
- C4H11NO amines: DEHA 3710-84-7, MOPA 5332-73-0 and AMP 124-68-5 share one formula but not one CAS number.
- Zinc orthophosphate: 7779-90-0, never 7779-90-1.
Product Standards in the Database: AWWA, EN and 21 CFR 173.310#
The standards column names the ANSI/AWWA B-series product standard, one of 49, and the CEN/TC 164 EN product standard for each chemical. NSF/ANSI/CAN 60 covers health effects and AWWA covers product quality, so utilities usually require both.
Ferrous chloride, hydrochloric acid, sulfuric acid, hydrogen peroxide, the phosphonates and sodium bisulfite have no AWWA standard; aluminum chlorohydrate is supplied under B408-25. Every edition is listed under AWWA B-series standards.
EN 881:2004 and EN 883:2004 are withdrawn and replaced by EN 17034:2018, and a cell without a year cites the number until the edition is confirmed. The catalogue is summarized under EN standards for drinking water treatment chemicals.
Which database chemicals are listed in 21 CFR 173.310 for boiler steam?#
21 CFR 173.310 lists the boiler water additives allowed where steam contacts food, and it caps 4 amines in steam: cyclohexylamine and morpholine at 10 ppm, DEAE at 15 ppm and octadecylamine at 3 ppm, excluding steam that contacts milk and milk products. Hydrazine is held to zero in steam, trisodium NTA to 5 ppm and polymaleic acid to 1 ppm in feedwater.
Unlisted rows read "not listed in 21 CFR 173.310", including carbohydrazide, DEHA and MOPA. Listing rules are set out in 21 CFR 173.310.
How to Choose Water Treatment Chemicals with the Database#
Choosing water treatment chemicals with the database takes 5 checks: function, system, certification, standard, then the chemical's own page. The 5 steps are listed below.
- Pick the function, such as coagulation or dechlorination, and open its family table.
- Narrow the rows by system, such as cooling, boiler or RO.
- Check certification: drinking water needs NSF/ANSI/CAN 60 (NSF/ANSI/CAN 61 for media), and food-plant steam needs a 21 CFR 173.310 listing.
- Confirm the AWWA or EN standard a purchase specification can cite.
- Open the chemical's page for doses, forms, hazards and sourcing.
Chemical programs by application combine rows, such as a scale inhibitor, corrosion inhibitor and biocide in one cooling tower, and are compared under chemical programs by application.
From the chemical to a supplier or program provider#
A chemical supplier sells a named chemical by grade and strength, while a program provider designs, doses and monitors a full treatment program.
Distributors and manufacturers are listed under water treatment chemical suppliers.
What to compare before you choose a program provider is covered under how to choose a program provider.
How Is the Water Treatment Chemical Database Updated? Data Date, Sources and News#
The database carries NSF/ANSI/CAN 60 and 61 values as of 2026-10-20, re-checked every quarter and before each chemical page publishes, together with AWWA and EN editions. The sources are the NSF listings, the AWWA standards list, the CEN/TC 164/WG 9 catalogue, eCFR, PubChem and ECHA. Rule dates, NSF revisions and AWWA editions that change a row are reported in water treatment chemicals news.
Which Chemicals Are Not in the Database?#
The database excludes 3 kinds of chemicals: chemicals covered as a section of a host page, chemicals without a water treatment role, and swimming pool, spa, household and other non-industrial products. Section-only chemicals appear on their host's page: potassium alum with aluminum sulfate, ammonium chloride with ammonium sulfate, performic acid with peracetic acid, PACS and PASS with polyaluminum chloride. Potassium hydroxide, calcium chloride and sodium chloride appear only in standards and pH tables.
What are some common chemicals used in potable water treatment?#
Common chemicals used in potable water treatment are coagulants (alum, ferric chloride, polyaluminum chloride), disinfectants (sodium hypochlorite, chlorine, monochloramine), pH and corrosion control chemicals (hydrated lime, caustic soda, zinc orthophosphate) and fluorosilicic acid.
Why utilities choose each of them is explained under drinking water treatment chemicals.
Is there a CAS number database for water treatment chemicals?#
Yes: this database gives the CAS number of 122 of the 124 water treatment chemicals, with salt and hydrate forms, checked against PubChem and ECHA. Tannin and manganese greensand read "not yet verified" until a number is confirmed.
Can I get the list of water treatment chemicals as a PDF or CSV?#
No PDF or CSV file is offered at launch: the full list is published as the 17 tables on this page, with the same columns and the NSF listing date of 2026-10-20.
Does an NSF/ANSI/CAN 60 listing mean EPA approval?#
No: an NSF/ANSI/CAN 60 listing is a third-party certification, not an EPA approval, because EPA replaced its Additives Advisory Program with this route in 1988 (53 FR 25586, 1988-07-07). Certifiers accredited under NSF/ANSI 223, such as NSF, UL Solutions and Kiwa, issue it.