Sodium Hydroxide

Strongly alkaline (1 % solution)

pH of a 0.05% wt/wt solution about 12; 0.5% solution about 13; 5% solution about 14

1.5 at 68 °F (USCG, 1999) - Denser than water; will sink

2.13 at 68 °F (USCG, 1999) - Denser than water; will sink

2.13 g/cu cm 25 °C

70-73 % solution: MP 62 °C; Density = 2.0 at 15.5 °C

2.1 g/cm³

2.13

White, orthogonal crystals

Colorless to white ... solid (flakes, beads, granular form).

Brittle, white, translucent crystalline solid

111 % (NIOSH, 2024)

easily soluble in cold water, hot water

Very soluble in water. Freely soluble in ethanol

1 g dissolves in 7.2 mL absolute alcohol, 4.2 mL methanol; also soluble in glycerol

1 g dissolves in 0.9 mL water, 0.3 mL boiling water

Solubility in water, g/100ml at 20 °C: 109 (very good)

greater than 266 °F at 760 mmHg (USCG, 1999)

Very high (USCG, 1999)

1388

1388 °C

1388 °C

2534 °F

604 °F (USCG, 1999)

323

323 °C

318 °C

605 °F

323 °C

Danger

H314: Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]

P260, P264, P280, P301+P330+P331, P302+P361+P354, P304+P340, P305+P354+P338, P316, P321, P363, P405, and P501 (click each P-code to see the statement)

This chemical does not meet GHS hazard criteria for < 0.1% (4 of 6949) of reports.

Chemical: Sodium hydroxide (Na(OH))

Hazard Traits - Dermatotoxicity; Ocular Toxicity; Respiratory Toxicity；Authoritative List - OEHHA RELs；Report - if used as a fragrance or flavor ingredient

Regulation (EC) No 1831/2003 (amended)

Sodium hydroxide (Na(OH)) is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of Sodium hydroxide (Na(OH)) are required to report information about their production and use of this chemical to the EPA under the Toxic Substances Control Act (TSCA). (40 eCFR Part 711)

2004/129/EC

Status: Active Update: 11-05-2023 https://echa.europa.eu/registration-dossier/-/registered-dossier/15566；Status: Active Update: 13-07-2021 https://echa.europa.eu/registration-dossier/-/registered-dossier/24304；Status: Cease Manufacture Update: 29-05-2013 https://echa.europa.eu/registration-dossier/-/registered-dossier/7515

Corrosive

Corrosive

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)

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)

· 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.

· 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.

· 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.

· 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.

Causes severe burns of eyes, skin, and mucous membranes. (USCG, 1999)

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)

· 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.

· 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.

· 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.

· 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.

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. It is commonly present in commercial drain and oven cleaners.

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]

1824 154

1823 154

1824 154

1823 154

1823 154(dry, solid)

1824 154(solution)

Substance added directly to human food affirmed as generally recognized as safe (GRAS).

Sodium hydroxide used as a general purpose food additive in animal drugs, feeds, and related products is generally recognized as safe when used in accordance with good manufacturing or feeding practice.

Bases, Strong；Water and Aqueous Solutions

Bases, Strong

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:；SMALL FIRE: Dry chemical, CO2 or water spray.；LARGE FIRE: Dry chemical, CO2, alcohol-resistant foam or water spray. If it can be done safely, move undamaged containers away from the area around the fire. Dike runoff from fire control for later disposal.；FIRE INVOLVING TANKS, RAIL TANK CARS OR HIGHWAY TANKS: Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles. Do not get water inside containers. Cool containers with flooding quantities of water until well after fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks in direct contact with flames. (ERG, 2024)

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:；SMALL FIRE: Dry chemical, CO2 or water spray.；LARGE FIRE: Dry chemical, CO2, alcohol-resistant foam or water spray. If it can be done safely, move undamaged containers away from the area around the fire. Dike runoff from fire control for later disposal.；FIRE INVOLVING TANKS, RAIL TANK CARS OR HIGHWAY TANKS: Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles. Do not get water inside containers. Cool containers with flooding quantities of water until well after fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks in direct contact with flames. (ERG, 2024)

In case of fire in the surroundings, use appropriate extinguishing media.

Fresh air, rest. Refer immediately for medical attention.

Remove contaminated clothes. Rinse skin with plenty of water or shower for at least 15 minutes. Refer immediately for medical attention.

First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

Rinse mouth. Do NOT induce vomiting. If within a few minutes after ingestion, one small glass of water may be given to drink. Refer immediately for medical attention.

· CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not available or no answer, refer to appropriate telephone number listed on the inside back cover.；· Keep unauthorized personnel away.；· Stay upwind, uphill and/or upstream.；· Ventilate closed spaces before entering, but only if properly trained and equipped.

· ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area.；· Do not touch damaged containers or spilled material unless wearing appropriate protective clothing.；· Stop leak if you can do it without risk.；· Prevent entry into waterways, sewers, basements or confined areas.；· Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers.；· DO NOT GET WATER INSIDE CONTAINERS.

· CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not available or no answer, refer to appropriate telephone number listed on the inside back cover.；· Keep unauthorized personnel away.；· Stay upwind, uphill and/or upstream.；· Ventilate closed spaces before entering, but only if properly trained and equipped.

· ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area.；· Do not touch damaged containers or spilled material unless wearing appropriate protective clothing.；· Stop leak if you can do it without risk.；· Prevent entry into waterways, sewers, basements or confined areas.；· Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers.；· DO NOT GET WATER INSIDE CONTAINERS.

· CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not available or no answer, refer to appropriate telephone number listed on the inside back cover.；· Keep unauthorized personnel away.；· Stay upwind, uphill and/or upstream.；· Ventilate closed spaces before entering, but only if properly trained and equipped.

· ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area.；· Do not touch damaged containers or spilled material unless wearing appropriate protective clothing.；· Stop leak if you can do it without risk.；· Prevent entry into waterways, sewers, basements or confined areas.；· Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers.；· DO NOT GET WATER INSIDE CONTAINERS.

(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)

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. If breathing has stopped, perform artificial respiration. Keep the affected person warm and at rest. Get medical attention as soon as possible.；Swallow: MEDICAL ATTENTION IMMEDIATELY - If this chemical has been swallowed, get medical attention immediately. (NIOSH, 2024)

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).；-- If no pulse detected or no respiratory medical device available, provide continuous compressions. Conduct a pulse check every two minutes or monitor for any signs of spontaneous respirations.；· Remove and isolate contaminated clothing and shoes.；· For minor skin contact, avoid spreading material on unaffected skin.；· In case of contact with substance, remove immediately by flushing skin or eyes with running water for at least 20 minutes.；· For severe burns, immediate medical attention is required.；· Effects of exposure (inhalation, ingestion, or skin contact) to substance may be delayed.；· Keep victim calm and warm.；· Keep victim under observation.；· For further assistance, contact your local Poison Control Center.；· Note: Basic Life Support (BLS) and Advanced Life Support (ALS) should be done by trained professionals.；Specific First Aid:；· For corrosives, in case of contact, immediately flush skin or eyes with running water for at least 30 minutes. Additional flushing may be required.

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).；-- If no pulse detected or no respiratory medical device available, provide continuous compressions. Conduct a pulse check every two minutes or monitor for any signs of spontaneous respirations.；· Remove and isolate contaminated clothing and shoes.；· For minor skin contact, avoid spreading material on unaffected skin.；· In case of contact with substance, remove immediately by flushing skin or eyes with running water for at least 20 minutes.；· For severe burns, immediate medical attention is required.；· Effects of exposure (inhalation, ingestion, or skin contact) to substance may be delayed.；· Keep victim calm and warm.；· Keep victim under observation.；· For further assistance, contact your local Poison Control Center.；· Note: Basic Life Support (BLS) and Advanced Life Support (ALS) should be done by trained professionals.；Specific First Aid:；· For corrosives, in case of contact, immediately flush skin or eyes with running water for at least 30 minutes. Additional flushing may be required.

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).；-- If no pulse detected or no respiratory medical device available, provide continuous compressions. Conduct a pulse check every two minutes or monitor for any signs of spontaneous respirations.；· Remove and isolate contaminated clothing and shoes.；· For minor skin contact, avoid spreading material on unaffected skin.；· In case of contact with substance, remove immediately by flushing skin or eyes with running water for at least 20 minutes.；· For severe burns, immediate medical attention is required.；· Effects of exposure (inhalation, ingestion, or skin contact) to substance may be delayed.；· Keep victim calm and warm.；· Keep victim under observation.；· For further assistance, contact your local Poison Control Center.；· Note: Basic Life Support (BLS) and Advanced Life Support (ALS) should be done by trained professionals.；Specific First Aid:；· For corrosives, in case of contact, immediately flush skin or eyes with running water for at least 30 minutes. Additional flushing may be required.

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).；-- If no pulse detected or no respiratory medical device available, provide continuous compressions. Conduct a pulse check every two minutes or monitor for any signs of spontaneous respirations.；· Remove and isolate contaminated clothing and shoes.；· For minor skin contact, avoid spreading material on unaffected skin.；· In case of contact with substance, remove immediately by flushing skin or eyes with running water for at least 20 minutes.；· For severe burns, immediate medical attention is required.；· Effects of exposure (inhalation, ingestion, or skin contact) to substance may be delayed.；· Keep victim calm and warm.；· Keep victim under observation.；· For further assistance, contact your local Poison Control Center.；· Note: Basic Life Support (BLS) and Advanced Life Support (ALS) should be done by trained professionals.；Specific First Aid:；· For corrosives, in case of contact, immediately flush skin or eyes with running water for at least 30 minutes. Additional flushing may be required.

· Wear positive pressure self-contained breathing apparatus (SCBA).；· Wear chemical protective clothing that is specifically recommended by the manufacturer when there is NO RISK OF FIRE.；· Structural firefighters' protective clothing provides thermal protection but only limited chemical protection.

· Wear positive pressure self-contained breathing apparatus (SCBA).；· Wear chemical protective clothing that is specifically recommended by the manufacturer when there is NO RISK OF FIRE.；· Structural firefighters' protective clothing provides thermal protection but only limited chemical protection.

· Wear positive pressure self-contained breathing apparatus (SCBA).；· Wear chemical protective clothing that is specifically recommended by the manufacturer when there is NO RISK OF FIRE.；· Structural firefighters' protective clothing provides thermal protection but only limited chemical protection.

· Wear positive pressure self-contained breathing apparatus (SCBA).；· Wear chemical protective clothing that is specifically recommended by the manufacturer when there is NO RISK OF FIRE.；· Structural firefighters' protective clothing provides thermal protection but only limited chemical protection.

Extinguish fire using agent suitable for surrounding fire. Use water spray to keep fire-exposed containers cool.

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.

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.

Volumetric sodium hydroxide soln used in laboratory must be protected from air to avoid formation of carbonate.

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.

On/in soil (solid): Construct barriers to convert or divert to impervious surface. Promptly shovel into steel containers.

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.

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.

Environmental considerations - Water spill: Use natural barriers or oil spill control booms to limit spill travel. Neutralize with dilute acid.

For more Cleanup Methods (Complete) data for SODIUM HYDROXIDE (6 total), please visit the HSDB record page.

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:；ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area. Do not touch damaged containers or spilled material unless wearing appropriate protective clothing. Stop leak if you can do it without risk. Prevent entry into waterways, sewers, basements or confined areas. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. DO NOT GET WATER INSIDE CONTAINERS. (ERG, 2024)

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:；ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area. Do not touch damaged containers or spilled material unless wearing appropriate protective clothing. Stop leak if you can do it without risk. Prevent entry into waterways, sewers, basements or confined areas. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. DO NOT GET WATER INSIDE CONTAINERS. (ERG, 2024)

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.

Following neutralization either at the spill site or at a waste management facility, the resultant sludge can be disposed of in a secure landfill.

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. If it is not practicable to manage the chemical in this fashion, it must be evaluated in accordance with EPA 40 CFR Part 261, specifically Subpart B, in order to determine the appropriate local, state and federal requirements for disposal.

Put into large vessel containing water. Neutralize with HCL /hydrochloric acid/. Discharge into the sewer with sufficient water. Recommendable methods: Neutralization & discharge to sewer. Peer review: Dilute greatly (< pH 9) before discharge. (Peer-review conclusions of an IRPTC expert consultation (May 1985))

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.

An experimental study was conducted to investigate the effects of erythropoietin on the acute phase of esophageal burn damage induced by sodium hydroxide. A standard esophageal alkaline burn was produced by the application of 10% sodium hydroxide to the distal esophagus in an in vivo rat model. Fifty-six female rats were allocated into three groups: Group BC (baseline control, n = 8) rats were uninjured and untreated, Group PC (positive control, n = 24) rats were injured but untreated and Group EPO (erythropoietin-treated, n = 24) rats were injured and given subcutaneous erythropoietin (1,000 IU/kg per day), 15 min, 24, and 48 hr after administration of the NaOH solution. Six animals from Group PC and six from Group EPO were killed at 4, 24, 48, and 72 hr after application of NaOH to the esophagus. All of animals in Group BC were killed 4 hr after exposure to 0.9% NaCl. Oxidative damage was assessed by measuring levels of malondialdehyde (MDA) and nitric oxide (NO), and activities of superoxide dismutase (SOD) and catalase (CAT) in homogenized samples of esophageal tissue. Histologic damage to esophageal tissue was scored by a single pathologist blind to groups. MDA levels in the BC and EPO groups were significantly lower than those in the PC group (p < 0.05). CAT and SOD activities, and NO levels in the BC and EPO groups were significantly higher than in the PC group (p < 0.05). Esophageal tissue damage measured at 4, 24, 48, and 72 hr after NaOH application was significantly less in the EPO group than in the PC group (p < 0.05). When administered early after an esophageal burn induced by 10% sodium hydroxide in this rat model, erythropoietin significantly attenuated oxidative damage, as measured by biochemical markers and histologic scoring.

SRP4: Interacts with acid salts to form bases.

... Esophageal burns were induced in male rats by the administration of 10% sodium hydroxide. Lipid peroxidation (LPO) products were then measured at the following times: 0, 1, 6, 24, 48 and 72 hr after treatment. Tissue hydroxyproline (HP) concentrations in the injured area were assessed at 14 days after the administration of sodium hydroxide. The groups received either systemic melatonin or normal saline. There were two, non-ischemic, sham control groups treated with or without melatonin. LPO products, malondialdehyde (MDA) and 4-hydroxyalkenal (4-HDA), increased immediately after the administration of sodium hydroxide; this indicates the participation of free radicals in the development of damage. Melatonin diminished the oxidative response and the amount of HP in the late phase of the lesion. Melatonin reduced oxidative damage in the early phase of the esophageal burns induced by sodium hydroxide.

/SRP: Experimental/ The gastric damaging effects of necrotizing concn of sodium hydroxide were strongly reduced by paracetamol. ... Paracetamol might be protective by stimulating the biosynthesis of prostaglandins in the stomach wall.

For more Interactions (Complete) data for SODIUM HYDROXIDE (6 total), please visit the HSDB record page.

EC50; Species: Ceriodaphnia dubia (Water Flea) age <24 hr neonate; Conditions: freshwater, static, 23 °C; Concentration: 40380 ug/L for 48 hr (95% confidence interval: 34590-47130 ug/L); Effect: intoxication, immobilization /100% purity/

LC50; Species: Carassius auratus (Goldfish); Conditions: freshwater, static; Concentration: 160000 ug/L for 24 hr

LC100; Species: Cyprinus carpio; Concentration: 180 ppm for 24 hr at 25 °C /Conditions of bioassay not specified in source examined/

LC50; Species: Poecilia reticulata (Guppy) age 3-4 week young organisms; Conditions: saltwater, renewal, 24 °C, pH >9.8-<10.0, salinity 2.8%, dissolved oxygen > or =70% saturated; Concentration: 209000 ug/L for 24 hr (95% confidence interval: 153000-286000 ug/L) /98.6% purity/

For more Ecotoxicity Values (Complete) data for SODIUM HYDROXIDE (6 total), please visit the HSDB record page.

AQUATIC FATE: In the case of a solid, anhydrous sodium hydroxide spill on soil, ground water pollution will occur if precipitation occurs prior to clean up. Precipitation will dissolve some of the solid (with much heat given off) and create an aqueous solution of sodium hydroxide, which then would be able to infiltrate the soil. However, prediction of the concentration and properties of the solution produced would be difficult.

Serious local effects by all routes of exposure.

inhalation, ingestion, skin and/or eye contact

The CIR Expert Panel concluded that ... Sodium Hydroxide is safe in hair straighteners and depilatories under conditions of recommended use; users should minimize skin contact.  These ingredients are safe for all other present practices of use and concentration described in this safety assessment when formulated to be nonirritating.

Safe for use in cosmetics, with qualifications

/AQUATIC SPECIES/ Concentration 20-100 mg/L in water kills some species of aquatic wildlife due to increase in pH.

/AQUATIC SPECIES/ Chronic exposure of guppies to sodium hydroxide (> or =25 mg/L) decreased their survival rate and weight gain, and caused either late or premature sexual maturity resulting in decreased fertility.

Cough. Sore throat. Burning sensation. Shortness of breath.

Redness. Pain. Serious skin burns. Blisters.

Redness. Pain. Blurred vision. Severe burns.

Abdominal pain. Burns in mouth and throat. Burning sensation in the throat and chest. Nausea. Vomiting. Shock or collapse.

irritation eyes, skin, mucous membrane; pneumonitis; eye, skin burns; temporary loss of hair

Estimated emissions of sodium hydroxide as one of the typical pollutants released from the synthetic organic chemical manufacturing industry (production/processing) may range from (unit process, product): alkylation, ethylbenzene, 1.9 to 21.5; condensation, polyethylene terephthalate, 0.065 to 23.1; dehydrogenation, isoprene, 0.5 to 19; dehydrohalogenation, vinylidene chloride, 45.5 to 605.5; polymerization, polyethylene terephthalate, 0.1 to 23.1 (all in g/kg produced)(1). The compound was spilled at an estimated 3,500 gallons into the Newark Bay on October 1991 from the Gist Brocades facility(2). Sodium hydroxide was involved in 2.6% of 6,928 chemical accidents in the US over a 5 year period up to 1985 at a reportable quantity of 2200 kg(3).

The skin, eyes, and respiratory tract should receive special attention in any placement or periodic examination. NIOSH recommends that workers subject to sodium hydroxide exposure have comprehensive preplacement medical examinations. Medical examinations shall be made available promptly to all workers with signs or symptoms of skin, eye, or upper respiratory tract irritation resulting from exposure to sodium hydoxide.

Chemical: Sodium hydroxide (Na(OH))

Hazard Traits - Dermatotoxicity; Ocular Toxicity; Respiratory Toxicity；Authoritative List - OEHHA RELs；Report - if used as a fragrance or flavor ingredient

Regulation (EC) No 1831/2003 (amended)

Sodium hydroxide (Na(OH)) is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of Sodium hydroxide (Na(OH)) are required to report information about their production and use of this chemical to the EPA under the Toxic Substances Control Act (TSCA). (40 eCFR Part 711)

2004/129/EC

Status: Active Update: 11-05-2023 https://echa.europa.eu/registration-dossier/-/registered-dossier/15566；Status: Active Update: 13-07-2021 https://echa.europa.eu/registration-dossier/-/registered-dossier/24304；Status: Cease Manufacture Update: 29-05-2013 https://echa.europa.eu/registration-dossier/-/registered-dossier/7515

Substance added directly to human food affirmed as generally recognized as safe (GRAS).

Sodium hydroxide used as a general purpose food additive in animal drugs, feeds, and related products is generally recognized as safe when used in accordance with good manufacturing or feeding practice.

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.

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 animals. Use: neutralizer. Limit: none.

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 requirements for reregistration (or the guidelines for generating such data) change.

As the federal pesticide law FIFRA directs, EPA is conducting a comprehensive review of older pesticides to consider their health and environmental effects and make decisions about their continued use. Under this pesticide reregistration program, EPA examines newer health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether the use of the pesticide does not pose unreasonable risk in accordance to newer saftey standards, such as those described in the Food Quality Protection Act of 1996. Pesticides for which EPA had not issued Registration Standards prior to the effective date of FIFRA '88 were divided into three lists based upon their potential for human exposure and other factors, with List B containing pesticides of greater concern than those on List C, and with List C containing pesticides of greater concern than those on List D. Sodium hydroxide is found on List D. Case No: 4065; Pesticide type: fungicide, herbicide, antimicrobial; Case Status: RED Approved 09/92; OPP has made a decision that some/all uses of the pesticide are eligible for reregistration, as reflected in a Reregistration Eligibility Decision (RED) document .; Active ingredient (AI): sodium hydroxide; Data Call-in (DCI) Date(s): 09/30/92; AI Status: OPP has completed a Reregistration Eligibility Decision (RED) document for the case/AI.

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).

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.

Because of its high-level alkalinity, sodium hydroxide in aqueous solution directly causes bond breakage in proteins (especially disulfide bridges). Hair and fingernails are found to be dissolved after 20 hours of direct contact with sodium hydroxide at pH values higher than 9.2. Sodium hydroxide has depilatory effects which have been described after accidental contact with solutions in the workplace. The breakage of bonds in proteins may lead to severe necrosis to the application site. The level of corrosion depends on the period of contact with the tissue, and on the concentration of sodium hydroxide.

Strong alkaline chemicals that destroy soft body tissues resulting in a deep, penetrating type of burn, in contrast to corrosives, that result in a more superficial type of damage via chemical means or inflammation. Caustics are usually hydroxides of light metals. SODIUM HYDROXIDE and potassium hydroxide are the most widely used caustic agents in industry. Medically, they have been used externally to remove diseased or dead tissues and destroy warts and small tumors. The accidental ingestion of products (household and industrial) containing caustic ingredients results in thousands of injuries per year.

There are no quantitative data for the absorption of sodium hydroxide through the skin. Solutions which contain 50 % sodium hydroxide have been shown to be corrosive and lethal when applied dermally to mice.

ALKALIS PENETRATE SKIN SLOWLY.

Ammonium hydroxide penetrates fastest, followed by sodium hydroxide, potassium hydroxide, and finally calcium hydroxide.

CIR ingredient: Sodium Hydroxide

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]

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]

Textile arts [Category: Hobbies]；Applying metallic patinas [Category: Hobbies]

Both oil base and water base fracturing fluids are being used in the fracturing industry. Water base, which includes alcohol-water mixtures and low strength acids, make up the majority of treating fluids. The common chemicals added to these fluids are polymers for viscosity development, crosslinkers for viscosity enhancement, pH control chemicals, gel breakers for polymer degradation following the treatment, surfactants, clay stabilizers, alcohol, bactericides, fluid loss additives and friction reducer. /Hydraulic fracturing/

Hydraulic fracturing uses a specially blended liquid which is pumped into a well under extreme pressure causing cracks in rock formations underground. These cracks in the rock then allow oil and natural gas to flow, increasing resource production. ... Chemical Name: Sodium hydroxide; Chemical Purpose: Adjusts the pH of fluid to maintain the effectiveness of other components, such as crosslinkers; Product Function: pH Adjusting agent.

(1972) 1.1X10+12 GRAMS

(1975) 1.00X10+12 GRAMS

(1984) 1.14X10+12 g

1996: 2 million tons.

(1972) 9.53X10+10 GRAMS

(1975) 9.8X10+10 GRAMS

(1984) 4.78X10+11 g

1996: 540,000 tons

2023: 20,000,000,000 - <25,000,000,000 lb；2022: 20,000,000,000 - <25,000,000,000 lb；2021: 20,000,000,000 - <25,000,000,000 lb；2020: 20,000,000,000 - <25,000,000,000 lb

(1972) 9.27X10+12 GRAMS

(1975) 8.7X10+12 GRAMS

(1985) 9.24X10+12 g

(1990) 24.06 billion lb

For more U.S. Production (Complete) data for SODIUM HYDROXIDE (12 total), please visit the HSDB record page.

51% IS CONSUMED IN CHEMICAL PROCESSING AND METAL PROCESSING OTHER THAN ALUMINUM; 6% FOR ALUMINUM PROCESSING; 18% IS USED IN PAPER AND PULP MANUFACTURE; 13% IS USED IN THE PETROLEUM, TEXTILE, SOAP, AND FOOD INDUSTRIES; 4% IS USED IN RAYON AND CELLOPHANE PRODUCTION; 8% IS USED IN OTHER APPLICATIONS (1974).

CHEMICAL PROFILE: Caustic soda. Organic Chemicals, 30%; Inorganic Chemicals, 20%; Pulp & Paper, 20%; Exports, 10%; Soaps and Detergents, 5%; Petroleum, 5%; Textiles, 4%; Alumina, 3%; Other, 3% (1986).

CHEMICAL PROFILE: Caustic soda. Pulp and paper, 22%; organic chemicals, 20%; inorganic chemicals, 11%; soaps and detergents, 7%; petroleum, 7%; water treatment, 7%; textiles, 5%; alumina, 4%; other, 9%; exports, 8%.

Direct application, 55% (pulp & paper, 24%; soaps and detergents, 10%; alumina, 6%; petroleum, 7%; textiles, 5%; water treatment, 5%; miscellaneous, 43%); organic chemicals 36% (propylene oxide, 23%; polycarbonates, 5%; ethyleneamines, 3%; epoxy resins, 3%; miscellaneous, 66%); inorganic chemicals, 9% (sodium/calcium hypochlorite, 24%; sulfur-containing compounds, 14%; sodium cyanide, 10%; miscellaneous 52%)

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

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

By reacting calcium hydroxide with sodium carbonate; from sodium chloride by electrolysis; from sodium metal and water vapor at low temperature.

Sodium hydroxide is produced industrially mainly by the electrolysis of sodium chloride. This yields sodium hydroxide solution, chlorine, and hydrogen in the mass ratios 1:0.88:0.025.

Solid sodium hydroxide (caustic soda) is obtained by evaporating sodium hydroxide solution until the water content is < 0.5 - 1.5 wt%. The most efficient utilization of energy is achieved with multistage equipment.

Causticization of sodium carbonate: A hot, ca. 12% solution of sodium carbonate is mixed with quicklime (CaO). The calcium carbonate that precipitates out is removed and the ca. 12% solution of sodium hydroxide is evaporated in several stages.

For more Methods of Manufacturing (Complete) data for SODIUM HYDROXIDE (6 total), please visit the HSDB record page.

Solid sodium hydroxide is supplied in the form of flakes, prills, cast blocks, and less commonly as tablets, briquettes, or granules.

Grades: commercial; ground; flake; beads; Food Chemical Codex grade; granulated (60% and 76% Na2O); rayon (low in iron, copper, and manganese); purified by alcohol (sticks, lumps, and drops); reagent; highest purity: CP, USP.

When kept in tight containers, the usual grades contain 97-98% sodium hydroxide.

Anhydrous (Rayon Grade) 99.0% minimum; Rayon Grade: 50% liquid; Regular Grade: 50% liquid, 47.7-51% purity.

For more Formulations/Preparations (Complete) data for SODIUM HYDROXIDE (8 total), please visit the HSDB record page.

Cosmetics product ingredient: Sodium hydroxide；Reason for Listing: Identified with non-cancer endpoints and listed with an inhalation or oral Reference Exposure Level by the California Office of Environmental Health Hazard Assessment under Health and Safety Code section 44360(b)(2)；Potential Health Impacts: Dermatotoxicity, Ocular Toxicity, and Respiratory Toxicity；Product count: 1292

Information on 1896 consumer products that contain Sodium hydroxide in the following categories is provided:；• Auto Products；• Commercial / Institutional；• Home Maintenance；• Inside the Home；• Landscaping/Yard；• Personal Care；• Pesticides；• Pet Care

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

Food Additives -> ACIDITY_REGULATOR -> JECFA Functional Classes

Food Additives -> ACIDITY_REGULATOR -> JECFA Functional Classes