Safety data summary
Sodium Hydroxide
Sodium Hydroxide (CAS 1310-73-2) is a chemical substance with the molecular formula HNaO and a molecular weight of 39.997 g/mol. Under the EU harmonised GHS classification (CLP Annex VI), it carries the signal word “Danger” and is classified as corrosive. Its label shows the Corrosion pictogram. Key hazard statements include H314 (causes severe skin burns and eye damage). The OSHA permissible exposure limit (PEL) is 2 mg/m³.
Hazards at a glance
- H314Causes severe skin burns and eye damage
Regulation (EC) No 1272/2008 of the European Parliament and of the Council — harmonised classification (CLP Annex VI)
1Identification
- Name
- Sodium Hydroxide
- IUPAC name
- sodium hydroxide
- CAS number
- 1310-73-2
- EC number
- 215-185-5
- Molecular formula
- HNaO
- Molecular weight
- 39.997 g/mol
- InChIKey
- HEMHJVSKTPXQMS-UHFFFAOYSA-M
- SMILES
- [OH-].[Na+]
- PubChem CID
- 14798
- Synonyms
- SODIUM HYDROXIDE, Caustic soda, Sodium hydrate, Aetznatron, Soda lye, White caustic, Soda, caustic, Natriumhydroxid, Rohrputz, Plung, Collo-Grillrein, Collo-Tapetta, Fuers Rohr, Rohrreiniger Rofix
Recommended uses
- CIR ingredient: Sodium HydroxideCosmetic Ingredient Review (CIR)
- Used to neutralize acids, produce sodium salts, hydrolyze fats to make soaps, and precipitate metals; large amounts are used in petroleum refining, rayon production, and rubber reclaiming; [Merck Index # 8627] Also used in metal cleaning, electroplating, processing cotton fabrics, and bleaching; [ATSDR Medical Management] Used in photography (developing bath); [www.ci.tucson.az.us/arthazards/medium.html] In semiconductor manufacturing, sodium hydroxide is used to develop the pattern in the photoresists and also as a wet echant. [CHS, p. 44-5] Caustic soda is used in hide preparation for leather production; [PMID 21938525]Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
- Acid and Alkali Cleaning of Metals [Category: Clean] Electroplating [Category: Plate] Petroleum Production and Refining [Category: Industry] Semiconductor Manufacturing [Category: Industry] Smelting Copper or Lead [Category: Industry] Textiles (Fiber & Fabric Manufacturing) [Category: Industry] Leather Tanning and Processing [Category: Industry] Photographic Processing [Category: Other] Textiles (Printing, Dyeing, or Finishing) [Category: Industry] Metal Extraction and Refining [Category: Industry]Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
- Soil amendments (fertilizers) Ion exchange agent Catalyst Diluent Not Known or Reasonably Ascertainable Thickening agent Corrosion inhibitor Stabilizing agent Reducing agent Cleaning agent Dye Softener and conditioner Adsorbent Defoamer Intermediate Anti-scaling agent Processing aids, specific to petroleum production Adhesion/cohesion promoter Etching agent Flocculating agent Chelating agent Leaching agent Lubricating agent Other Sizing agent CBI Swelling agent Anti-freeze agent Anti-adhesive/cohesive Solvent Fuel agents pH regulating agent Antioxidant Bleaching agent Chemical reaction regulator Plating agent Processing aids, not otherwise listed Processing aids not otherwise specifiedEPA Chemical Data Reporting (CDR)
- Adhesion/cohesion promoter Etching agent Flocculating agent Intermediate Processing aids, specific to petroleum production Oxidizing agent Laboratory chemicals Dye Cleaning agent Plasticizer Stabilizing agent Soil amendments (fertilizers) Catalyst Ion exchange agent Not Known or Reasonably Ascertainable Processing aids not otherwise specified Surfactant (surface active agent) Chemical reaction regulator Fuel agents pH regulating agent Bleaching agent Solvent Dispersing agent Anti-freeze agent Anti-adhesive/cohesive Other Lubricating agentEPA Chemical Data Reporting (CDR)
Use categories: EPA Safer Chemical Functional Use Classes -> Processing Aids and Additives · Safer Chemical Classes -> Green circle - The chemical has been verified to be of low concern · Food additives · Fragrance Ingredients
Description
- At room temperature, sodium hydroxide is a white crystalline odorless solid that absorbs moisture from the air. It is a manufactured substance. When dissolved in water or neutralized with acid it liberates substantial heat, which may be sufficient to ignite combustible materials. Sodium hydroxide is very corrosive. It is generally used as a solid or a 50% solution. Other common names include caustic soda and lye. Sodium hydroxide is used to manufacture soaps, rayon, paper, explosives, dyestuffs, and petroleum products. It is also used in processing cotton fabric, laundering and bleaching, metal cleaning and processing, oxide coating, electroplating, and electrolytic extracting.Agency for Toxic Substances and Disease Registry (ATSDR)
- Sodium hydroxide solution appears as a colorless liquid. More dense than water. Contact may severely irritate skin, eyes, and mucous membranes. Toxic by ingestion. Corrosive to metals and tissue.CAMEO Chemicals
- Sodium hydroxide, solid appears as a white solid. Corrosive to metals and tissue. Used in chemical manufacturing, petroleum refining, cleaning compounds, drain cleaners.CAMEO Chemicals
2Hazard identification
- Signal word
- Danger
- Pictograms
- GHS05
- Classification source
- Regulation (EC) No 1272/2008 of the European Parliament and of the Council
Precautionary statements
| Code | Statement |
|---|---|
| P260 | Do not breathe dust/fume/gas/mist/vapors/spray. |
| P264 | Wash hands [and ...] thoroughly after handling. |
| P280 | Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/... |
| P301+P330+P331 | IF SWALLOWED: Rinse mouth. Do NOT induce vomiting. |
| P302+P361+P354 | IF ON SKIN: Take off Immediately all contaminated clothing. Immediately rinse with water for several minutes. |
| P304+P340 | IF INHALED: Remove person to fresh air and keep comfortable for breathing. |
| P305+P354+P338 | IF IN EYES: Immediately rinse with water for several minutes. Remove contact lenses if present and easy to do. Continue rinsing. |
| P316 | Get emergency medical help immediately. |
| P321 | Specific treatment (see ... on this label). |
| P363 | Wash contaminated clothing before reuse. |
| P405 | Store locked up. |
| P501 | Dispose of contents/container to ... |
Other reported classifications
6 classification records exist across sources. Differences usually reflect purity, physical form or impurities.
| Source | Signal | Hazard codes |
|---|---|---|
| European Chemicals Agency (ECHA) | Danger | H290, H314, H315, H318, H319 |
| European Chemicals Agency (ECHA) | Danger | H290, H314, H318 |
| NITE-CMC | Danger | H314, H318, H370 |
| NITE-CMC | Danger | H314, H318, H370 |
NFPA 704 rating
- 3 - Materials that, under emergency conditions, can cause serious or permanent injury.Hazardous Substances Data Bank (HSDB)
- 0 - Materials that will not burn under typical fire conditions, including intrinsically noncombustible materials such as concrete, stone, and sand.Hazardous Substances Data Bank (HSDB)
- 1 - Materials that in themselves are normally stable but that can become unstable at elevated temperatures and pressures.Hazardous Substances Data Bank (HSDB)
Health hazards
- Causes severe burns of eyes, skin, and mucous membranes. (USCG, 1999)CAMEO Chemicals
- Strong corrosive action on contacted tissues. INHALATION: dust may cause damage to upper respiratory tract and lung itself, producing from mild nose irritation to pneumonitis. INGESTION: severe damage to mucous membranes; severe scar formation or perforation may occur. EYE CONTACT: produces severe damage. (USCG, 1999)CAMEO Chemicals
- · TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe injury or death. · Contact with molten substance may cause severe burns to skin and eyes. · Avoid any skin contact. · Fire may produce irritating, corrosive and/or toxic gases. · Runoff from fire control or dilution water may be corrosive and/or toxic and cause environmental contamination.Emergency Response Guidebook (ERG)
Fire hazards
- Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]: Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Corrosives in contact with metals may evolve flammable hydrogen gas. Containers may explode when heated. For electric vehicles or equipment, ERG Guide 147 (lithium ion or sodium ion batteries) or ERG Guide 138 (sodium batteries) should also be consulted. (ERG, 2024)CAMEO Chemicals
- · Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. · Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). · Corrosives in contact with metals may evolve flammable hydrogen gas. · Containers may explode when heated. · For electric vehicles or equipment, GUIDE 147 (lithium ion or sodium ion batteries) or GUIDE 138 (sodium batteries) should also be consulted.Emergency Response Guidebook (ERG)
- Not combustible. Contact with moisture or water may generate sufficient heat to ignite combustible materials. Risk of fire and explosion on contact with incompatible substances. See Chemical Dangers.ILO-WHO International Chemical Safety Cards (ICSCs)
Hazards summary
- At room temperature, sodium hydroxide is a white crystalline odorless solid that absorbs moisture from the air. It is a manufactured substance. When dissolved in water or neutralized with acid it liberates substantial heat, which may be sufficient to ignite combustible materials. Sodium hydroxide is very corrosive. It is generally used as a solid or a 50% solution. Other common names include caustic soda and lye. Sodium hydroxide is used to manufacture soaps, rayon, paper, explosives, dyestuffs, and petroleum products. It is also used in processing cotton fabric, laundering and bleaching, metal cleaning and processing, oxide coating, electroplating, and electrolytic extracting.Agency for Toxic Substances and Disease Registry (ATSDR)
- Liquid causes second or third degree burns after short contact; [CHRIS] In studies using rabbits, instillation by oral intubation caused within 10 seconds: erosion into the stomach muscle with 12% solutions; perforation with 28% solutions; and no damage with 1% solutions. Application to the skin of a 5% solution caused severe necrosis after 4 hours. Application of a 1% solution to the eyes caused no damage if the eyes were immediately irrigated. [ACGIH] Solutions > 30% are highly corrosive to skin. [Quick CPC] Inhalation of the aerosol can cause pulmonary edema. [ICSC]Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
3Composition / information on ingredients
| Substance | CAS | EC | Formula |
|---|---|---|---|
| Sodium Hydroxide | 1310-73-2 | 215-185-5 | HNaO |
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
- (Act quickly) EYES: flush with water at once for at least 15 min. SKIN: flush with water, then rinse with dilute vinegar (acetic acid). INGESTION: give water and milk. Do NOT induce vomiting. Call physician at once, even when injury seems to be slight. (USCG, 1999)CAMEO Chemicals
- Excerpt from NIOSH Pocket Guide for Sodium hydroxide: 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: WATER FLUSH IMMEDIATELY - If this chemical contacts the skin, immediately flush the contaminated skin with water. If this chemical penetrates the clothing, immediately remove the clothing and flush the skin with water. Get medical attention promptly. Breathing: RESPIRATORY SUPPORT - If a person breathes large amounts of this chemical, move the exposed person to fresh air at once.CAMEO Chemicals
- General First Aid: · Call 911 or emergency medical service. · Ensure that medical personnel are aware of the material(s) involved, take precautions to protect themselves and avoid contamination. · Move victim to fresh air if it can be done safely. · Administer oxygen if breathing is difficult. · If victim is not breathing: -- DO NOT perform mouth-to-mouth resuscitation; the victim may have ingested or inhaled the substance. -- If equipped and pulse detected, wash face and mouth, then give artificial respiration using a proper respiratory medical device (bag-valve mask, pocket mask equipped with a one-way valve or other device).Emergency Response Guidebook (ERG)
- (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: Water flush immediately - If this chemical contacts the skin, immediately flush the contaminated skin with water. If this chemical penetrates the clothing, immediately remove the clothing and flush the skin with water. Get medical attention promptly. Breathing: Respiratory support Swallow: Medical attention immediately - If this chemical has been swallowed, get medical attention immediately.The National Institute for Occupational Safety and Health (NIOSH)
Symptoms of exposure
- Cough. Sore throat. Burning sensation. Shortness of breath.ILO-WHO International Chemical Safety Cards (ICSCs)
- Redness. Pain. Serious skin burns. Blisters.ILO-WHO International Chemical Safety Cards (ICSCs)
- Redness. Pain. Blurred vision. Severe burns.ILO-WHO International Chemical Safety Cards (ICSCs)
5Fire-fighting measures
- Extinguish fire using agent suitable for surrounding fire. Use water spray to keep fire-exposed containers cool.Hazardous Substances Data Bank (HSDB)
- If material on fire or involved in fire: Extinguish fire using agent suitable for type of surrounding fire. (Material itself does not burn or burns with difficulty.) Use "alcohol" foam, dry chemical or carbon dioxide. Keep run-off water out of sewers and water sources.Hazardous Substances Data Bank (HSDB)
6Accidental release measures
Isolation and evacuation
- Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]: IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids. SPILL: Increase the immediate precautionary measure distance, in the downwind direction, as necessary. FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2024)CAMEO Chemicals
- Immediate precautionary measure · Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids. Spill · For highlighted materials: see Table 1 - Initial Isolation and Protective Action Distances. · For non-highlighted materials: increase the immediate precautionary measure distance, in the downwind direction, as necessary. Fire · If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions.Emergency Response Guidebook (ERG)
Spill cleanup
- Personal protection: chemical protection suit including self-contained breathing apparatus. Do NOT let this chemical enter the environment. Sweep spilled substance into covered plastic containers. Carefully collect remainder. Then store and dispose of according to local regulations.ILO-WHO International Chemical Safety Cards (ICSCs)
- On/in soil (solid): Construct barriers to convert or divert to impervious surface. Promptly shovel into steel containers.Hazardous Substances Data Bank (HSDB)
- Soil, Liquid: Absorb small amounts of spill with sand, vermiculite or other inert absorbant material; Shovel into steel containers. May also remove material with vacuum equipment.Hazardous Substances Data Bank (HSDB)
- Environment considerations - Land spill:: Dig a pit, pond, lagoon, or holding area to contain liquid or solid material. Dike surface flow using soil, sand bags, foamed polyurethane, or foamed concrete. Absorb bulk liquid with fly ash of cement powder.Hazardous Substances Data Bank (HSDB)
7Handling and storage
- Separated from food and feedstuffs, strong acids and metals. Store only in original container. Dry. Well closed. Store in an area without drain or sewer access.ILO-WHO International Chemical Safety Cards (ICSCs)
- CONTAINERS SHOULD BE STORED IN ROOMS WITH TRAPPED FLOOR DRAINS TOWARDS WHICH FLOORS SHOULD BE SLANTED. WHERE FLOOR DRAINS ARE NOT PROVIDED, CURBS OR DRAINED GUTTER, COVERED WITH ... GRILL, SHOULD BE CONSTRUCTED @ DOOR OPENINGS.Hazardous Substances Data Bank (HSDB)
- Volumetric sodium hydroxide soln used in laboratory must be protected from air to avoid formation of carbonate.Hazardous Substances Data Bank (HSDB)
- Store in a cool, dry, well-ventilated location. Separate from organic and oxidizing materials, acids, metal powders. Immediately remove and properly dispose of any spilled material.Hazardous Substances Data Bank (HSDB)
8Exposure controls / personal protection
| Limit | Value | Source |
|---|---|---|
| OSHA PEL | 2.0 [mg/m3] | Haz-Map, Information on Hazardous Chemicals and Occupational Diseases |
| OSHA PEL | 2 mg/m³ | Occupational Safety and Health Administration (OSHA) |
| NIOSH REL | 2 mg/m³ | Occupational Safety and Health Administration (OSHA) |
| NIOSH REL | C 2 mg/m3 | The National Institute for Occupational Safety and Health (NIOSH) |
| ACGIH TLV | 2.0 [mg/m3] | Haz-Map, Information on Hazardous Chemicals and Occupational Diseases |
| ACGIH TLV | Ceiling Limit: 2 mg/cu m. | Hazardous Substances Data Bank (HSDB) |
| IDLH | 10 mg/m3 [From NPG: Sodium hydroxide] (NIOSH, 2024) | CAMEO Chemicals |
| IDLH | 10 mg/m3 (NIOSH, 2024) | CAMEO Chemicals |
Personal protective equipment
- Wide-brimmed hat; safety goggles with rubber side shields; tight-fitting cotton clothing; rubber gloves under shirt cuffs; rubber boots and apron. (USCG, 1999)CAMEO Chemicals
- Excerpt from NIOSH Pocket Guide for Sodium hydroxide: Skin: PREVENT SKIN CONTACT - Wear appropriate personal protective clothing to prevent skin contact. Eyes: PREVENT EYE CONTACT - Wear appropriate eye protection to prevent eye contact. Wash skin: WHEN CONTAMINATED - The worker should immediately wash the skin when it becomes contaminated. Remove: WHEN WET OR CONTAMINATED - Work clothing that becomes wet or significantly contaminated should be removed and replaced. Change: DAILY - Workers whose clothing may have become contaminated should change into uncontaminated clothing before leaving the work premises.CAMEO Chemicals
- Hazards from spills and leaks should be minimized by an adequate supply of water for washing-down. ... Adequate ventilation should be provided in areas where caustic ... soda mist or dust is present. ... For the protection of the eyes, safety goggles should be worn, as well as face shields, if complete face protection is necessary. Eyewash fountains and safety showers must be available at any location where eye and/or skin contact can occur. Protection against mist or dust of this compound can be provided by filter or dust-type respiratory protective equipment. ... Safety shoes ... are recommended.Hazardous Substances Data Bank (HSDB)
- Respirator selection: 100 mg/cu m: a) High-efficiency particulate respirator with a full facepiece, b) Supplied air respirator with a full facepiece, helmet, or hood. , c) Self-contained breathing apparatus with a full facepiece. 200 mg/cu m: a) Powered air-purifying respirator with a high-efficiency filter with a full facepiece, or b) Type C SA with a full facepiece operated in pressure-demand or other positive pressure mode or with a full facepiece, helmet, or hood operated in continuous- flow mode. . Escape: a) Dust and mist respirator, except single-use respirators with full facepiece, or b) Self-contained breathing apparatus with a full facepiece.Hazardous Substances Data Bank (HSDB)
Respirator recommendations
- NIOSH/OSHA Up to 10 mg/m3 : (APF = 25) Any supplied-air respirator operated in a continuous-flow mode/ (APF = 50) Any air-purifying, full-facepiece respirator with an N100, R100, or P100 filter. Click here for information on selection of N, R, or P filters. (APF = 25) Any powered, air-purifying respirator with a high-efficiency particulate filter. (APF = 50) Any self-contained breathing apparatus with a full facepiece (APF = 50) Any supplied-air respirator with a full facepiece Emergency or planned entry into unknown concentrations or IDLH conditions: (APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressur…The National Institute for Occupational Safety and Health (NIOSH)
9Physical and chemical properties
| Molecular weight | 39.997 g/mol |
|---|---|
| Physical description | Sodium hydroxide solution appears as a colorless liquid. More dense than water. Contact may severely irritate skin, eyes, and mucous membranes. Toxic by ingestion. Corrosive to metals and tissue. CAMEO Chemicals Sodium hydroxide, solid appears as a white solid. Corrosive to metals and tissue. Used in chemical manufacturing, petroleum refining, cleaning compounds, drain cleaners. CAMEO Chemicals |
| Color / form | White, orthogonal crystals Hazardous Substances Data Bank (HSDB) Colorless to white ... solid (flakes, beads, granular form). Hazardous Substances Data Bank (HSDB) |
| Odor | ... Odorless ... Hazardous Substances Data Bank (HSDB) |
| Boiling point | greater than 266 °F at 760 mmHg (USCG, 1999) CAMEO Chemicals Very high (USCG, 1999) CAMEO Chemicals 1388 DrugBank |
| Melting point | 604 °F (USCG, 1999) CAMEO Chemicals 323 DrugBank 323 °C Hazardous Substances Data Bank (HSDB) |
| Autoignition temperature | Not flammable (USCG, 1999) CAMEO Chemicals |
| Density / specific gravity | 1.5 at 68 °F (USCG, 1999) - Denser than water; will sink CAMEO Chemicals 2.13 at 68 °F (USCG, 1999) - Denser than water; will sink CAMEO Chemicals |
| Vapor pressure | 0 mmHg (approx) (NIOSH, 2024) CAMEO Chemicals VP: 1 Pa at 513 °C; 10 Pa at 605 °C; 100 Pa at 722 °C; 1kPa at 874 °C; 10 kPa at 1080 °C; 100 kPa at 1377 °C Hazardous Substances Data Bank (HSDB) |
| Solubility | 111 % (NIOSH, 2024) CAMEO Chemicals easily soluble in cold water, hot water DrugBank Very soluble in water. Freely soluble in ethanol EU Food Improvement Agents |
| Viscosity | 4.0 cP at 350 °C Hazardous Substances Data Bank (HSDB) |
| pH | Strongly alkaline (1 % solution) EU Food Improvement Agents |
| Decomposition | When heated to decomposition it emits toxic fumes of /sodium oxide/. Hazardous Substances Data Bank (HSDB) |
| Explosive / flammable limits | Noncombustible Solid, but when in contact with water may generate sufficient heat to ignite combustible materials. The National Institute for Occupational Safety and Health (NIOSH) |
10Stability and reactivity
Reactivity
- SODIUM HYDROXIDE SOLUTION refers to an aqueous solution of sodium hydroxide. Strongly basic. Reacts rapidly and exothermically with organic and inorganic acids, with organic and inorganic acid anhydrides, including oxides of nonmetals such as sulfur dioxide, sulfur trioxide, phosphorus trioxide, phosphorus pentaoxide, and with organic and inorganic acid chlorides. May react explosively with maleic anhydride [MCA Case History 622 1960]. Attacks aluminum and zinc with evolution of hydrogen, a flammable gas. May initiate polymerization in polymerizable organic materials: a violent polymerization results if acetaldehyde contacts alkaline materials such as sodium hydroxide;CAMEO Chemicals
- SODIUM HYDROXIDE (Caustic Soda) is a strong base. Reacts rapidly and exothermically with acids, both organic and inorganic. Readily absorbs moisture from the air to give caustic semi-solids that attack aluminum and zinc with the evolution of flammable hydrogen gas. Catalyzes the polymerization of acetaldehyde and other polymerizable compounds; these reactions can occur violently, for example, acrolein polymerizes with extreme violence when put in contact with alkaline materials such as sodium hydroxide [Chem. Safety Data Sheet SD-85 1961]. Reacts with great violence with phosphorus pentaoxide when initiated by local heating [Mellor 8 Supp.3:406 1971].CAMEO Chemicals
- Slowly absorbs carbon dioxide from the air to give solid products as crusts or precipitates. Water soluble. Dilution with water liberates heat, possibly enough to cause local boiling and spattering.CAMEO Chemicals
Incompatible materials and hazardous reactions
- GENERATES CONSIDERABLE HEAT WHEN ... SOLN IS MIXED WITH ACID.Hazardous Substances Data Bank (HSDB)
- CRUDE HYDROQUINONE WAS PUMPED INTO SODIUM HYDROXIDE STORAGE TANK BY MISTAKE. THE HYDROQUINONE LIQUOR AT 85 °C DECOMP RAPIDLY IN THE PRESENCE OF THE SODIUM HYDROXIDE RESULTING IN OVERFLOW OF TANK & EVOLUTION OF CONSIDERABLE AMOUNT OF HEAT.Hazardous Substances Data Bank (HSDB)
- Much heat is evolved when the solid material is dissolved in water. Therefore, cold water and caution must be used for this process.Hazardous Substances Data Bank (HSDB)
Chemical stability
- CONTAINERS OF LYE MUST BE TIGHTLY CLOSED TO PREVENT CONVERSION TO SODIUM CARBONATE BY CARBON DIOXIDE OF AIR.Hazardous Substances Data Bank (HSDB)
11Toxicological information
Target organs
- Eyes, skin, respiratory systemThe National Institute for Occupational Safety and Health (NIOSH)
Short-term exposure effects
- The substance is corrosive to the eyes, skin and respiratory tract. Corrosive on ingestion.ILO-WHO International Chemical Safety Cards (ICSCs)
Long-term exposure effects
- Repeated or prolonged contact with skin may cause dermatitis.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 harm/injury/toxicity 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 and plant life; and conformance with environmental and public health regulations.Hazardous Substances Data Bank (HSDB)
- Following neutralization either at the spill site or at a waste management facility, the resultant sludge can be disposed of in a secure landfill.Hazardous Substances Data Bank (HSDB)
- SRP: Wastewater from contaminant suppression, cleaning of protective clothing/equipment, or contaminated sites should be contained and evaluated for subject chemical or decomposition product concentrations. Concentrations shall be lower than applicable environmental discharge or disposal criteria. Alternatively, pretreatment and/or discharge to a permitted wastewater treatment facility is acceptable only after review by the governing authority and assurance that "pass through" violations will not occur. Due consideration shall be given to remediation worker exposure (inhalation, dermal and ingestion) as well as fate during treatment, transfer and disposal.Hazardous Substances Data Bank (HSDB)
14Transport information
Shipping name
- IMO 8.0; Sodium hydroxide solid; Sodium hydroxide solutionHazardous Substances Data Bank (HSDB)
- UN 1823; Sodium hydroxide, solidHazardous Substances Data Bank (HSDB)
DOT hazard class
- Caustic soda, (etc.) see Sodium hydroxide etcUS Code of Federal Regulations, Hazardous Materials, 49 CFR Part 172
- Sodium hydroxide, solidUS Code of Federal Regulations, Hazardous Materials, 49 CFR Part 172
- UN1823US Code of Federal Regulations, Hazardous Materials, 49 CFR Part 172
DOT label
- CorrosiveCAMEO Chemicals
UN classification
- UN Hazard Class: 8; UN Pack Group: IIILO-WHO International Chemical Safety Cards (ICSCs)
Emergency Response Guidebook
- 1824 154Emergency Response Guidebook (ERG)
- 1823 154Emergency Response Guidebook (ERG)
15Regulatory information
- Residues of sodium hydroxide 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 or to raw agricultural commodities after harvest. Use: neutralizer. Limit: none.Hazardous Substances Data Bank (HSDB)
- The Agency has completed its review of all available information, and has determined that the data are sufficient to support reregistration of products containing sodium hydroxide. ... The Agency therefore finds that products containing sodium hydroxide as an active ingredient are eligible for reregistration. ... Although the Agency has found that certain products containing sodium hydroxide are eligible for registration, it should be understood that the Agency may take appropriate regulatory action, and/or require the submission of additional data to support the registration of products containing sodium hydroxide, if new information comes to the Agency's attention or if the data requiremen…Hazardous Substances Data Bank (HSDB)
- Sodium hydroxide is designated as a hazardous substance under section 311(b)(2)(A) of the Federal Water Pollution Control Act and further regulated by the Clean Water Act Amendments of 1977 and 1978. These regulations apply to discharges of this substance. This designation includes any isomers and hydrates, as well as any solutions and mixtures containing this substance.Hazardous Substances Data Bank (HSDB)
- Persons in charge of vessels or facilities are required to notify the National Response Center (NRC) immediately, when there is a release of this designated hazardous substance, in an amount equal to or greater than its reportable quantity of 1000 lb or 454 kg. The toll free number of the NRC is (800) 424-8802. The rule for determining when notification is required is stated in 40 CFR 302.4 (section IV.D.3.b).Hazardous Substances Data Bank (HSDB)
- Substance added directly to human food affirmed as generally recognized as safe (GRAS).Hazardous Substances Data Bank (HSDB)
Overview of SDS regulations (OSHA HazCom, WHMIS, REACH/CLP) →
16Other information
Compiled from PubChem CID 14798 and the sources it aggregates (attributed inline). Data retrieved 2026-10-12. This summary describes the pure substance and is not a supplier SDS.
Frequently asked questions about Sodium Hydroxide
What is the CAS number for Sodium Hydroxide?
The CAS Registry Number for Sodium Hydroxide is 1310-73-2. Its EC (EINECS) number is 215-185-5. It is transported under UN 1823 / UN 1824.
Is Sodium Hydroxide hazardous?
Yes. Sodium Hydroxide is classified under GHS with the signal word “Danger”. Hazard statements: H314: Causes severe skin burns and eye damage.
Which GHS pictograms apply to Sodium Hydroxide?
Sodium Hydroxide labels carry GHS05 (Corrosion).
What are the workplace exposure limits for Sodium Hydroxide?
OSHA PEL: 2 mg/m³. NIOSH REL: 2 mg/m³. ACGIH TLV: Ceiling Limit: 2 mg/cu m. IDLH: 10 mg/m3 [From NPG: Sodium hydroxide] (NIOSH, 2024).
What PPE is needed when handling Sodium Hydroxide?
Wide-brimmed hat; safety goggles with rubber side shields; tight-fitting cotton clothing; rubber gloves under shirt cuffs; rubber boots and apron. (USCG, 1999)
What is the first aid for Sodium Hydroxide exposure?
(Act quickly) EYES: flush with water at once for at least 15 min. SKIN: flush with water, then rinse with dilute vinegar (acetic acid). INGESTION: give water and milk. Do NOT induce vomiting. Call physician at once, even when injury seems to be slight. (USCG, 1999)
How should Sodium Hydroxide be stored?
Separated from food and feedstuffs, strong acids and metals. Store only in original container. Dry. Well closed. Store in an area without drain or sewer access.