{
  "$schema": "https://foodadditiveindex.com/api/v1/schema.json",
  "id": "https://foodadditiveindex.com/additives/sodium-hydroxide",
  "slug": "sodium-hydroxide",
  "name": "Sodium hydroxide",
  "identifiers": {
    "e_number": "E524",
    "ins_number": "524",
    "cas_number": "1310-73-2",
    "inchikey": "HEMHJVSKTPXQMS-UHFFFAOYSA-M",
    "pubchem_cid": 14798
  },
  "functional_class": "Acidity regulator",
  "summary": "Sodium hydroxide, or lye, is a strongly alkaline processing aid. It gives pretzels their crust and colour, cures olives, and produces hominy from maize; it is normally neutralised or washed out.",
  "derivation_summary": "Manufactured by the electrolysis of brine. It is corrosive as supplied and is handled as a processing aid rather than an ingredient.",
  "regulatory_status": [
    {
      "jurisdiction": "US",
      "jurisdiction_name": "United States",
      "authority": "Food and Drug Administration",
      "status": "permitted",
      "status_label": "Permitted",
      "provision_count": 1,
      "provisions": [
        {
          "status": "permitted",
          "food_category": null,
          "max_level": null,
          "max_level_unit": null,
          "conditions": null,
          "effective_from": null,
          "citation": {
            "ref": "21 CFR 184.1763",
            "url": "https://www.ecfr.gov/current/title-21/section-184.1763"
          },
          "source": "ecfr",
          "retrieved_at": "2026-09-07T18:25:51.549Z"
        }
      ]
    },
    {
      "jurisdiction": "CODEX",
      "jurisdiction_name": "Codex Alimentarius",
      "authority": "Codex Alimentarius Commission / JECFA",
      "status": "permitted_with_conditions",
      "status_label": "Permitted, with conditions",
      "provision_count": 9,
      "provisions": [
        {
          "status": "permitted",
          "food_category": null,
          "max_level": null,
          "max_level_unit": "GMP",
          "conditions": null,
          "effective_from": "1999",
          "citation": {
            "ref": "CXS 192-1995 Table Three, INS 524",
            "url": "https://www.fao.org/fao-who-codexalimentarius/codex-texts/dbs/gsfa/en/"
          },
          "source": "gsfa",
          "retrieved_at": "2026-09-07T07:54:15.059Z"
        },
        {
          "status": "permitted_with_conditions",
          "food_category": {
            "system": "codex",
            "code": "01.1.2",
            "name": "Other Fluid Milk (plain)"
          },
          "max_level": null,
          "max_level_unit": "GMP",
          "conditions": "GSFA notes: 410",
          "effective_from": "2019",
          "citation": {
            "ref": "CXS 192-1995 Table One, INS 524, food category 01.1.2",
            "url": "https://www.fao.org/fao-who-codexalimentarius/codex-texts/dbs/gsfa/en/"
          },
          "source": "gsfa",
          "retrieved_at": "2026-09-07T07:54:15.059Z"
        },
        {
          "status": "permitted_with_conditions",
          "food_category": {
            "system": "codex",
            "code": "01.2.1.2",
            "name": "Fermented milks (plain), heat-treated after fermentation"
          },
          "max_level": null,
          "max_level_unit": "GMP",
          "conditions": null,
          "effective_from": "2013",
          "citation": {
            "ref": "CXS 192-1995 Table One, INS 524, food category 01.2.1.2",
            "url": "https://www.fao.org/fao-who-codexalimentarius/codex-texts/dbs/gsfa/en/"
          },
          "source": "gsfa",
          "retrieved_at": "2026-09-07T07:54:15.059Z"
        },
        {
          "status": "permitted_with_conditions",
          "food_category": {
            "system": "codex",
            "code": "01.8.2",
            "name": "Dried whey and whey products, excluding whey cheeses"
          },
          "max_level": null,
          "max_level_unit": "GMP",
          "conditions": "GSFA notes: XS331",
          "effective_from": "2023",
          "citation": {
            "ref": "CXS 192-1995 Table One, INS 524, food category 01.8.2",
            "url": "https://www.fao.org/fao-who-codexalimentarius/codex-texts/dbs/gsfa/en/"
          },
          "source": "gsfa",
          "retrieved_at": "2026-09-07T07:54:15.059Z"
        },
        {
          "status": "permitted_with_conditions",
          "food_category": {
            "system": "codex",
            "code": "02.2.1",
            "name": "Butter"
          },
          "max_level": null,
          "max_level_unit": "GMP",
          "conditions": null,
          "effective_from": "2008",
          "citation": {
            "ref": "CXS 192-1995 Table One, INS 524, food category 02.2.1",
            "url": "https://www.fao.org/fao-who-codexalimentarius/codex-texts/dbs/gsfa/en/"
          },
          "source": "gsfa",
          "retrieved_at": "2026-09-07T07:54:15.059Z"
        },
        {
          "status": "permitted_with_conditions",
          "food_category": {
            "system": "codex",
            "code": "13.1.1",
            "name": "Infant formulae"
          },
          "max_level": 2000,
          "max_level_unit": "mg/kg",
          "conditions": "GSFA notes: 55 & 551",
          "effective_from": "2026",
          "citation": {
            "ref": "CXS 192-1995 Table One, INS 524, food category 13.1.1",
            "url": "https://www.fao.org/fao-who-codexalimentarius/codex-texts/dbs/gsfa/en/"
          },
          "source": "gsfa",
          "retrieved_at": "2026-09-07T07:54:15.059Z"
        },
        {
          "status": "permitted_with_conditions",
          "food_category": {
            "system": "codex",
            "code": "13.1.2",
            "name": "Follow-up formulae"
          },
          "max_level": null,
          "max_level_unit": "GMP",
          "conditions": "GSFA notes: 316 & 551",
          "effective_from": "2026",
          "citation": {
            "ref": "CXS 192-1995 Table One, INS 524, food category 13.1.2",
            "url": "https://www.fao.org/fao-who-codexalimentarius/codex-texts/dbs/gsfa/en/"
          },
          "source": "gsfa",
          "retrieved_at": "2026-09-07T07:54:15.059Z"
        },
        {
          "status": "permitted_with_conditions",
          "food_category": {
            "system": "codex",
            "code": "13.1.3",
            "name": "Formulae for special medical purposes for infants"
          },
          "max_level": 2000,
          "max_level_unit": "mg/kg",
          "conditions": "GSFA notes: 55 & 551",
          "effective_from": "2026",
          "citation": {
            "ref": "CXS 192-1995 Table One, INS 524, food category 13.1.3",
            "url": "https://www.fao.org/fao-who-codexalimentarius/codex-texts/dbs/gsfa/en/"
          },
          "source": "gsfa",
          "retrieved_at": "2026-09-07T07:54:15.059Z"
        },
        {
          "status": "permitted_with_conditions",
          "food_category": {
            "system": "codex",
            "code": "13.2",
            "name": "Complementary foods for infants and young children"
          },
          "max_level": null,
          "max_level_unit": "GMP",
          "conditions": "GSFA notes: 320 & XS73",
          "effective_from": "2023",
          "citation": {
            "ref": "CXS 192-1995 Table One, INS 524, food category 13.2",
            "url": "https://www.fao.org/fao-who-codexalimentarius/codex-texts/dbs/gsfa/en/"
          },
          "source": "gsfa",
          "retrieved_at": "2026-09-07T07:54:15.059Z"
        }
      ]
    }
  ],
  "names": [
    {
      "name": "1310-73-2",
      "type": "cas",
      "source": "ecfr"
    },
    {
      "name": "81133-20-2",
      "type": "cas",
      "source": "pubchem"
    },
    {
      "name": "Aetznatron",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Ascarite",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Ascarite II",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Caswell No. 773",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Caustic soda",
      "type": "common",
      "source": "openfoodtox"
    },
    {
      "name": "Caustic soda, bead",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Caustic soda, dry",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Caustic soda, liquid",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Collo-Grillrein",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Collo-Tapetta",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "E 524",
      "type": "common",
      "source": "openfoodtox"
    },
    {
      "name": "EPA Pesticide Chemical Code 075603",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Fuers Rohr",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "HSDB 229",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Hydroxide, Sodium",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Hydroxyde de sodium",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "hydroxyl sodium",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "INS-524",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Lewis-red devil lye",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Liquid-plumr",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Lye",
      "type": "common",
      "source": "openfoodtox"
    },
    {
      "name": "NaOH",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Natrii hydroxydum",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Natrium causticum",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Natrium-hydroxid, reinstes",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Natriumhydroxid",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Natriumhydroxyde",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Plung",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Promoter 3308b",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Rohrputz",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Rohrreiniger Rofix",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Soda asbestos",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Soda lye",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Soda, caustic",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Soda, hydrate",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Soda, kaustische",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Sodio(idrossido di)",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "sodium hydoxide",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Sodium hydrate",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "sodium hydroxid",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Sodium hydroxide",
      "type": "common",
      "source": "openfoodtox"
    },
    {
      "name": "Sodium Hydroxide (0.1M in water (0.1N))",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Sodium hydroxide (Na(OH))",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Sodium hydroxide (Na2(OH)2)",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Sodium hydroxide dimer",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Sodium hydroxide pearls",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Sodium hydroxide, flake",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Sodium hydroxide, pellets",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Sodium hydroxide, solid",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Sodium hydroxide; NaOH",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "sodium hyroxide",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Sodium(hydroxyde de)",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "sodiumhydroxid",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "sodiumhydroxide",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "soude caustique",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Stamperprep",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "Tosoh pearl",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "UN 1823 (solid)",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "White caustic",
      "type": "common",
      "source": "pubchem"
    },
    {
      "name": "E524",
      "type": "e_number",
      "source": "openfoodtox"
    },
    {
      "name": "524",
      "type": "ins",
      "source": "gsfa"
    },
    {
      "name": "Sodium;hydroxide",
      "type": "iupac",
      "source": "openfoodtox"
    },
    {
      "name": "Sodium hydroxide",
      "type": "label",
      "source": "ecfr"
    }
  ],
  "hazard_reference_values": [],
  "sources": [
    {
      "key": "ecfr",
      "name": "Electronic Code of Federal Regulations, Title 21",
      "publisher": "U.S. Government Publishing Office / National Archives",
      "licence": "Public domain",
      "url": "https://www.ecfr.gov/api/versioner/v1/full/2026-08-31/title-21.xml",
      "retrieved_at": "2026-09-07T18:25:51.549Z"
    },
    {
      "key": "gsfa",
      "name": "Codex General Standard for Food Additives (CXS 192-1995)",
      "publisher": "Codex Alimentarius Commission (FAO/WHO)",
      "licence": "FAO terms — non-commercial use with attribution",
      "url": "https://www.fao.org/fao-who-codexalimentarius/codex-texts/dbs/gsfa/en/",
      "retrieved_at": "2026-09-07T07:54:15.059Z"
    }
  ],
  "citation_policy": "Cite as: Food Additive Index, \"Sodium hydroxide\", https://foodadditiveindex.com/additives/sodium-hydroxide. This site reports regulatory status and does not rate additives.",
  "generated_at": "2026-09-08T00:09:38.694Z"
}