CAS 1303-96-4PubChem CID 16211214
Borax (B4Na2O7.10H2O)
- IUPAC name
- disodium;3,7-dioxido-2,4,6,8,9-pentaoxa-1,3,5,7-tetraborabicyclo[3.3.1]nonane;decahydrate
- Molecular formula
- B4H20Na2O17
- Molecular weight
- 381.4 g/mol
- Exact mass
- 382.0868084 Da
- Topological polar surface area
- 102.0 Ų
- Hydrogen-bond donors
- 10
- Hydrogen-bond acceptors
- 17
- Covalent units
- 13
- Defined stereocentres
- 0
Also known as
BORAXBorax decahydrateSodium borate decahydrateSodium pyroborate decahydrateAntipyoninBorascuBoricinSolubor
16 more reported names
TronaborJaikinNeoborBuraGerstley borateGertley borateBoro-spray91MBZ8H3QODisodium tetraborate decahydrateSodium borate, decahydrateSodium biborate decahydrateBoric acid (H2B4O7), disodium salt, decahydrateBoron sodium oxide (B4Na2O7), decahydratesodium diboratesodium meta borateBorax 200ck
External database identifiers
- ChEMBL:CHEMBL3833375
- EPA DTXSID:DTXSID701014356
- PubMed:10010
Evidence from additional scientific databases
NIH PubChem PUG-View
Exact identifier match16211214
Attributed physical-property, hazard, environmental and use annotations.
- Boiling Point: 608 °F Source: Occupational Safety and Health Administration (OSHA)
- Boiling Point: 608 °F Source: The National Institute for Occupational Safety and Health (NIOSH)
- Color/Form: White, monoclinic crystals Source: Hazardous Substances Data Bank (HSDB)
- Color/Form: Hard crystals, granules or crystalline powder; efflorescent in dry air, the crystals often being coated with white powder Source: Hazardous Substances Data Bank (HSDB)
- Color/Form: Crystalline granules or crystalline powder Source: Hazardous Substances Data Bank (HSDB)
- Color/Form: White, crystalline solid [Note: Becomes anhydrous at 608 degrees F] Source: Hazardous Substances Data Bank (HSDB)
- Density: 1.73 g/cu cm Source: Hazardous Substances Data Bank (HSDB)
- Density: Relative density (water = 1): 1.7 Source: ILO-WHO International Chemical Safety Cards (ICSCs)
- Density: 1.73 Source: Occupational Safety and Health Administration (OSHA)
- Density: 1.73 @25 °C Source: PAC Chemical Database, U.S. Department of Energy
- Density: 1.73 Source: The National Institute for Occupational Safety and Health (NIOSH)
- Melting Point: 75 °C (decomposes) Source: Hazardous Substances Data Bank (HSDB)
- Melting Point: 167 °F Source: Occupational Safety and Health Administration (OSHA)
- Melting Point: 167 °F Source: The National Institute for Occupational Safety and Health (NIOSH)
- Odor: Odorless Source: Hazardous Substances Data Bank (HSDB)
- Physical Description: Liquid; Other Solid; Large Crystals; Wet Solid; Dry Powder Source: EPA Chemical Data Reporting (CDR)
- Physical Description: White, odorless, crystalline solid; Becomes anhydrous at 608 degrees F; [NIOSH] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
- Physical Description: WHITE CRYSTALS OR CRYSTALLINE POWDER. Source: ILO-WHO International Chemical Safety Cards (ICSCs)
- Physical Description: White, odorless, crystalline solid. Source: Occupational Safety and Health Administration (OSHA)
- Physical Description: White, odorless, crystalline solid. [herbicide] [Note: Becomes anhydrous at 608 °F.] Source: The National Institute for Occupational Safety and Health (NIOSH)
- Refractive Index: Index of refraction: 1.447 (alpha); 1.469 (beta); 1.472 (gamma) Source: Hazardous Substances Data Bank (HSDB)
- Solubility: Aqueous solution is alkaline to litmus and phenolphthalein; pH about pH = 9.5 Source: Hazardous Substances Data Bank (HSDB)
- Solubility: At 100 °C loses 5H2O; at 150 °C loses 9H2O; becomes anhydrous at 320 °C; borax dissolves many metallic oxides when fused with them Source: Hazardous Substances Data Bank (HSDB)
- Solubility: In water, 5.93X10+4 mg/L at 25 °C Source: Hazardous Substances Data Bank (HSDB)
- Solubility: 3.17 g/100 g water at 25 °C Source: Hazardous Substances Data Bank (HSDB)
- Solubility: 1 g/16 mL in water; 1 g/0.6 mL boiling water; 1 g/1 mL glycerol; insoluble in alcohol Source: Hazardous Substances Data Bank (HSDB)
- Solubility: Insoluble in ethanol Source: Hazardous Substances Data Bank (HSDB)
- Solubility: 0.60 g/100 g acetone Source: Hazardous Substances Data Bank (HSDB)
- Solubility: Solubility in water, g/100ml at 20 °C: 5.1 Source: ILO-WHO International Chemical Safety Cards (ICSCs)
- Solubility: 6% Source: The National Institute for Occupational Safety and Health (NIOSH)
- Vapor Pressure: Approximately 0 mm Hg Source: Hazardous Substances Data Bank (HSDB)
- Vapor Pressure: 0 mmHg (approx) Source: Occupational Safety and Health Administration (OSHA)
- Vapor Pressure: 0 mmHg (approx) Source: The National Institute for Occupational Safety and Health (NIOSH)
- pH: pH at 20 °C: 9.3 (0.1% solution); 9.2 (1.0% solution) Source: Hazardous Substances Data Bank (HSDB)
- Exposure Routes: The substance can be absorbed into the body by inhalation and by ingestion. Source: ILO-WHO International Chemical Safety Cards (ICSCs)
- Exposure Routes: inhalation, ingestion, skin and/or eye contact Source: The National Institute for Occupational Safety and Health (NIOSH)
- First Aid: (General first aid procedures); Eye: Irrigate immediately - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately.; Skin: Soap wash - If this chemical contacts the skin, wash the contaminated skin with soap and water.; Breathing: Respiratory support; Swallow: Medical attention immediately - If this chemical has been swallowed, get medical attention immediately. Source: The National Institute for Occupational Safety and Health (NIOSH)
- Signal: Danger Source: Regulation (EC) No 1272/2008 of the European Parliament and of the Council
- GHS Hazard Statements: H360FD: May damage fertility; May damage the unborn child [Danger Reproductive toxicity] Source: Regulation (EC) No 1272/2008 of the European Parliament and of the Council
- Precautionary Statement Codes: P203, P280, P318, P405, and P501 (click each P-code to see the statement) Source: Regulation (EC) No 1272/2008 of the European Parliament and of the Council
- Note: This chemical does not meet GHS hazard criteria for < 0.1% (1 of 2865) of reports. Source: European Chemicals Agency (ECHA)
- Signal: Danger Source: European Chemicals Agency (ECHA)
- GHS Hazard Statements: H319 (12.6%): Causes serious eye irritation [Warning Serious eye damage/eye irritation]; H360 (93.2%): May damage fertility or the unborn child [Danger Reproductive toxicity] Source: European Chemicals Agency (ECHA)
- Precautionary Statement Codes: P203, P264+P265, P280, P305+P351+P338, P318, P337+P317, P405, and P501 (click each P-code to see the statement) Source: European Chemicals Agency (ECHA)
- ECHA C&L Notifications Summary: Aggregated GHS information provided per 2865 reports by companies from 31 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.; Reported as not meeting GHS hazard criteria per 1 of 2865 reports by companies.; There are 30 notifications provided by 2864 of 2865 reports by companies with hazard statement code(s).; Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown. For more detailed information, please visit ECHA C&L website. Source: European Chemicals Agency (ECHA)
- Signal: Danger Source: NITE-CMC
- GHS Hazard Statements: H315: Causes skin irritation [Warning Skin corrosion/irritation]; H319: Causes serious eye irritation [Warning Serious eye damage/eye irritation]; H335: May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]; H360: May damage fertility or the unborn child [Danger Reproductive toxicity]; H370: Causes damage to organs [Danger Specific target organ toxicity, single exposure]; H372: Causes damage to organs through prolonged or repeated exposure [Danger Specific target organ toxicity, repeated exposure]; H413: May cause long lasting harmful effects to aquatic life [Hazardous to the aquatic environment, long-term hazard] Source: NITE-CMC
- Precautionary Statement Codes: P203, P260, P261, P264, P264+P265, P270, P271, P273, P280, P302+P352, P304+P340, P305+P351+P338, P308+P316, P318, P319, P321, P332+P317, P337+P317, P362+P364, P403+P233, P405, and P501 (click each P-code to see the statement) Source: NITE-CMC
- GHS Hazard Statements: H303: May be harmful if swallowed [Warning Acute toxicity, oral]; H315: Causes skin irritation [Warning Skin corrosion/irritation]; H319: Causes serious eye irritation [Warning Serious eye damage/eye irritation]; H361: Suspected of damaging fertility or the unborn child [Warning Reproductive toxicity]; H370: Causes damage to organs [Danger Specific target organ toxicity, single exposure]; H372: Causes damage to organs through prolonged or repeated exposure [Danger Specific target organ toxicity, repeated exposure]; H373: May causes damage to organs through prolonged or repeated exposure [Warning Specific target organ toxicity, repeated exposure] Source: NITE-CMC
- Target Organs: Eyes, skin, respiratory system Source: The National Institute for Occupational Safety and Health (NIOSH)
- Cosmetic Ingredient Review Conclusion: The Expert Panel concludes that Sodium Borate and Boric Acid, in concentrations less than or equal to 5 percent, are safe as cosmetic ingredients when used as currently recommended; however, cosmetic formulations containing free Sodium Borate or Boric Acid at this concentration should not be used on infant skin or injured skin. Note: In 2003, the CIR Expert Panel considered available new data on these ingredients and reaffirmed the above conclusion. Source: Cosmetic Ingredient Review (CIR)
- Cosmetic Ingredient Review Finding(s): Safe for use in cosmetics, with qualifications Source: Cosmetic Ingredient Review (CIR)
- Environmental Bioconcentration: In a greenhouse experiment with sandy loam soil treated with 0-8.0 ppm boron as borax, boron toxicity symptoms appeared earliest in lentil plants and barley seedlings exposed to 8.0 ppm boron. In barley the severity of boron toxicity decreased with the decrease in boron levels, whereas in lentil the severity of the symptoms eventually reached the same level in 2 and 4 ppm boron treatments as with the highest concentration. Dry matter yield decreased 38.6% in lentil and 23.4% in barley exposed to 8.0 ppm boron in comparison with controls. Boron contents of lentil and barley plants on soil treated with 8 ppm boron were approximately 7- and approximately 8-fold those of control plants, respectively. Source: Hazardous Substances Data Bank (HSDB)
- Environmental Fate: TERRESTRIAL FATE: Boron is naturally occurring and ubiquitous in the environment. No microbial degradation. Disappearance from soil is by washing out. Persistence in soil is about 2 years, depending on rainfall and soil structure. Source: Hazardous Substances Data Bank (HSDB)
- Consumer Uses: Other; Adhesion/cohesion promoter; Soil amendments (fertilizers); Not Known or Reasonably Ascertainable; Flame retardant Source: EPA Chemical Data Reporting (CDR)
- Industry Uses: Abrasives; Plating agent; Etching agent; Chelating agent; Flame retardant; Soil amendments (fertilizers) Source: EPA Chemical Data Reporting (CDR)
- Cosmetic Ingredient Review Link: CIR ingredient: Sodium Borate Source: Cosmetic Ingredient Review (CIR)
- Sources/Uses: Used as a preservative, antiseptic and fungicide; also used to manufacture glazes, enamels, soldering fluxes and cleaning compounds and to fireproof textiles and wood; [ACGIH] Boric acid and borates as tablets or powder are used to kill larvae in barns and other insects in houses. Rarely, they are sprayed as herbicides. [EPA: Recognition of Pesticide Poisonings] Used in photo developing bath; [www.ci.tucson.az.us/arthazards/medium.html] Borax (borax decahydrate) is found naturally in some salt lakes and alkaline soils. Boric acid is formed by crystallizing a solution of hydrochloric acid or sulfuric acid and borax. [Hawley] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
- Industrial Processes with risk of exposure: Soldering [Category: Heat or Machine]; Using Disinfectants or Biocides [Category: Clean]; Farming (Pesticides) [Category: Industry]; Photographic Processing [Category: Other]; Textiles (Printing, Dyeing, or Finishing) [Category: Industry] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
- Uses: For borax (USEPA/OPP Pesticide Code: 011102) ACTIVE products with label matches. /SRP: Registered for use in the U.S. but approved pesticide uses may change periodically and so federal, state and local authorities must be consulted for currently approved uses./ Source: Hazardous Substances Data Bank (HSDB)
- Uses: Long been used as a mild antiseptic fungicide and as a herbicide ... Total control of vegetation on non-crop land, such as paths, giving long-term control. Also used in insect baits for food stores to control Formicidae. Source: Hazardous Substances Data Bank (HSDB)
- Uses: Soldering metals; manufacture of glazes and enamels; tanning; in cleaning compounds; artificially aging wood; as preservative, either alone or with other antiseptics against wood fungus; fireproofing fabrics and wood; curing and preserving skins; in cockroach control. In buffers; as a complexing or masking agent in analytical chemistry. Pharmaceutic aid (alkalizer). Source: Hazardous Substances Data Bank (HSDB)
- Uses: Used in ant poisons, for fly control around refuse and manure piles, as a larvicide, in manufacture of glazes, enamels, cleaning compounds, and in soldering metals Source: Hazardous Substances Data Bank (HSDB)
- Uses: For more Uses (Complete) data for BORAX (17 total), please visit the HSDB record page. Source: Hazardous Substances Data Bank (HSDB)
Mapped by: Existing checksum-valid CAS to unique PubChem CID match. Retrieved: 2026-08-31. Open source record
Scientific classifications and hazard annotations provide context and do not replace the market-specific regulatory decision shown above.
Additional source coverage and match status
| Source | Result | Checked |
|---|---|---|
| NIH PubChem PUG-View | Exact match | 2026-08-31 |
A recorded no-match is useful evidence that the source was checked; it is not a claim that the substance does not exist elsewhere.
Retrieved from NIH PubChem on 2026-08-31 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.