Boric Acid

1Identification

Name

Boric Acid

IUPAC name

boric acid

CAS number

10043-35-3

EC number

233-139-2

Molecular formula

BH3O3

Molecular weight

61.84 g/mol

InChIKey

KGBXLFKZBHKPEV-UHFFFAOYSA-N

SMILES

B(O)(O)O

PubChem CID

7628

Synonyms

BORIC ACID, Orthoboric acid, Boracic acid, Borofax, Boron hydroxide, Boric acid (H3BO3), Boron trihydroxide, Basilit B, Three Elephant, Boric acid (BH3O3), Trihydroxyborane, Trihydroxyborone, Flea Prufe, Super Flea Eliminator

Recommended uses

• CIR ingredient: Boric Acid
  Cosmetic Ingredient Review (CIR)
• Used as an insecticide to kill ants and roaches, as a soldering flux, a flame retardant and weatherproofing agent; also used as an additive to dyes, nickeling baths, film developers, glass, enamels, soaps, paints, paper, adhesives, and steel; [HSDB] Used as a flux, an additive for heat-resistant borosilcate glass and glass fibers, a flame retardant for textile and insulation products, a fungicide for citrus fruits, an eye medicine, and a solute for nickel electroplating baths; Boric acid is formed by crystallizing a solution of hydrochloric acid or sulfuric acid and borax.
  Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
• Steel Producing [Category: Industry] Welding [Category: Weld] Brazing [Category: Heat or Machine] Electroplating [Category: Plate] Textiles (Fiber & Fabric Manufacturing) [Category: Industry] Painting (Pigments, Binders, and Biocides) [Category: Paint] Applying Wood Preservatives [Category: Other] Using Disinfectants or Biocides [Category: Clean] Farming (Pesticides) [Category: Industry] Sewer and Wastewater Treatment [Category: Industry] Leather Tanning and Processing [Category: Industry] Photographic Processing [Category: Other] Cement Producing [Category: Industry] Textiles (Printing, Dyeing, or Finishing) [Category: Industry] Glass Manufacturing [Category: Industry]
  Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
• Processing aids not otherwise specified Plating agent Chemical reaction regulator Bleaching agent Fuel agents pH regulating agent Binder Other Lubricating agent Anti-static agent Chelating agent Etching agent Adhesion/cohesion promoter Surface modifier Dye Flux agent Flame retardant Cleaning agent Stabilizing agent Not Known or Reasonably Ascertainable Soil amendments (fertilizers)
  EPA Chemical Data Reporting (CDR)
• Chemical reaction regulator pH regulating agent Bleaching agent Tanning agents not otherwise specified Other Lubricating agent Anti-adhesive/cohesive Adhesion/cohesion promoter Anti-scaling agent Viscosity modifiers Soil amendments (fertilizers) Corrosion inhibitor Not Known or Reasonably Ascertainable
  EPA Chemical Data Reporting (CDR)

Use categories: EPA Safer Chemical Functional Use Classes -> Enzymes and Enzyme Stabilizers · Safer Chemical Classes -> Yellow triangle - The chemical has met Safer Choice Criteria for its functional ingredient-class, but has some hazard profile issues · Food additives · Food Additives -> PRESERVATIVE -> JECFA Functional Classes

Description

• Boric acid is an odorless white solid. Melting point 171 °C. Sinks and mixes with water. (USCG, 1999)
  CAMEO Chemicals
• Boric acid is a member of boric acids. It has a role as an astringent. It is a conjugate acid of a dihydrogenborate.
  ChEBI
• 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.
  Cosmetic Ingredient Review (CIR)

2Hazard identification

Signal word

Danger

Pictograms

GHS08

Classification source

Regulation (EC) No 1272/2008 of the European Parliament and of the Council

Precautionary statements

Other reported classifications

9 classification records exist across sources. Differences usually reflect purity, physical form or impurities.

Health hazards

• Although no adverse effects have been reported from inhaling boric acid dust, it is absorbed through mucous membranes. Ingestion of 5 grams or more may irritate gastrointestinal tract and affect central nervous system. Contact with dust or aqueous solutions may irritate eyes; no chronic effects have been recognized, but continued contact should be avoided. Dust and solutions are absorbed through burns and open wounds but not through unbroken skin. (USCG, 1999)
  CAMEO Chemicals

Fire hazards

• Literature sources indicate that this compound is nonflammable. (NTP, 1992)
  CAMEO Chemicals
• Not combustible. Gives off irritating or toxic fumes (or gases) in a fire.
  ILO-WHO International Chemical Safety Cards (ICSCs)

Hazards summary

• In typical cases of poisoning by ingestion, the victims have vomiting and diarrhea, skin desquamation, mucosal erosions, and injury to the liver and kidneys; Evidence of neurotoxicity includes seizures, delirium, and coma. The mechanism of toxicity is not known. [Ford, p. 750-1] A skin irritant; [Quick CPC] In high-dose reproductive studies of animals, boric acid causes testicular damage and fetal loss. [Frazier, p. 252-4] The basis for the TLV for inorganic borate compounds (including boric acid) is irritation of the nose and respiratory tract. Studies of workers exposed to sodium borate dusts found no evidence of pulmonary function or reproductive impairment.
  Haz-Map, Information on Hazardous Chemicals and Occupational Diseases

3Composition / information on ingredients

This page describes the pure substance. Commercial products may be solutions or mixtures. Check Section 3 of your supplier's SDS for concentrations and other ingredients.

4First-aid measures

• EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop. SKIN: IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water.
  CAMEO Chemicals

Symptoms of exposure

• Cough. Sore throat.
  ILO-WHO International Chemical Safety Cards (ICSCs)
• No acute symptoms expected.
  ILO-WHO International Chemical Safety Cards (ICSCs)
• Redness. Pain.
  ILO-WHO International Chemical Safety Cards (ICSCs)

5Fire-fighting measures

Not available in the public sources we compile. Check Section 5 of the supplier's SDS.

6Accidental release measures

Spill cleanup

• Personal protection: particulate filter respirator adapted to the airborne concentration of the substance. Sweep spilled substance into covered containers. If appropriate, moisten first to prevent dusting. Wash away remainder with plenty of water.
  ILO-WHO International Chemical Safety Cards (ICSCs)

7Handling and storage

• Separated from strong bases.
  ILO-WHO International Chemical Safety Cards (ICSCs)
• Preserve in well-closed containers.
  Hazardous Substances Data Bank (HSDB)

8Exposure controls / personal protection

Personal protective equipment

• Chemical goggles; chemical resistant gloves and clothing. (USCG, 1999)
  CAMEO Chemicals

9Physical and chemical properties

10Stability and reactivity

Reactivity

• BORIC ACID is a very weak acid. Incompatible with alkali carbonates and hydroxides. During an attempt to make triacetyl borate, a mixture of boric acid and acetic anhydride exploded when heated to 58-60 °C [Chem. Eng. News 51:(34) 1973]. Reacts violently with the strong reducing agent potassium metal.
  CAMEO Chemicals
• Water soluble.
  CAMEO Chemicals

Incompatible materials and hazardous reactions

• During an attempt to make triacetyl borate, a mixture of boric acid and acetic anhydride exploded when heated to 58-60 °C.
  Hazardous Substances Data Bank (HSDB)
• A mixture of potassium and /boric acid/ ... may explode on impact ...
  Hazardous Substances Data Bank (HSDB)
• Incompatible /with/ alkali carbonates and hydroxides.
  Hazardous Substances Data Bank (HSDB)

Chemical stability

• Stable in air.
  Hazardous Substances Data Bank (HSDB)

11Toxicological information

Short-term exposure effects

• The substance is irritating to the respiratory tract. May cause mechanical irritation to the eyes. The substance may cause effects on the central nervous system and kidneys. This may result in impaired functions.
  ILO-WHO International Chemical Safety Cards (ICSCs)

Long-term exposure effects

• Repeated or prolonged contact with skin may cause dermatitis. The substance may have effects on the testes. Animal tests show that this substance possibly causes toxicity to human reproduction or development.
  ILO-WHO International Chemical Safety Cards (ICSCs)

12Ecological information

Not available in the public sources we compile. Check Section 12 of the supplier's SDS.

13Disposal considerations

• SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal, aquatic, and plant life; and conformance with environmental and public health regulations.
  Hazardous Substances Data Bank (HSDB)

14Transport information

Not available in the public sources we compile. Check Section 14 of the supplier's SDS.

How DOT hazard classes work →

15Regulatory information

• Residues of boric acid are exempted from the requirement of a tolerance when used in accordance with good agricultural practice as inert (or occasionally active) ingredients in pesticide formulations applied to growing crops only. Use: sequestrant. Limit: none.
  Hazardous Substances Data Bank (HSDB)
• An exemption from the requirement of a tolerance is established for residues of the pesticidal chemical boric acid and its salts, borax (sodium borate decahydrate), disodium octaborate tetrahydrate, boric oxide (boric anhydride), sodium borate and sodium metaborate, in or on raw agricultural commodities when used as an active ingredient in insecticides, herbicides, or fungicides preharvest or postharvest in accordance with good agricultural practices.
  Hazardous Substances Data Bank (HSDB)
• Boric acid is an indirect food additive for use only as a component of adhesives.
  Hazardous Substances Data Bank (HSDB)

Overview of SDS regulations (OSHA HazCom, WHMIS, REACH/CLP) →

16Other information

Compiled from PubChem CID 7628 and the sources it aggregates (attributed inline). Data retrieved 2026-10-12. This summary describes the pure substance and is not a supplier SDS.