Provenance

Reference data from EU CLP Annex VI and published regulations — verify against your supplier's SDS before use.

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Substance profile

Sodium hydrogensulphite … %

Sodium hydrogensulphite … % is a white crystal or crystalline powder with a slight sulfurous odor.

CAS 7631-90-5 Warning

01 · Identification

What Sodium hydrogensulphite … % is

Sodium hydrogensulphite … % is a white crystal or crystalline powder with a slight sulfurous odor. It boils at 104 °C, melts at 0 °C.

Under the GHS it carries the signal word Warning. It is classed as corrosives.

02 · Identifiers

Sodium hydrogensulphite … % identifiers and molecular data

Sodium hydrogensulphite … % CAS number and EC number

CAS number7631-90-5
EC number231-548-0
Index number (CLP Annex VI)016-064-00-8

Sodium hydrogensulphite … % molecular formula and molecular weight

Chemical class Corrosives

Other names for Sodium hydrogensulphite … %

  • sodium hydrogensulphite … %
  • sodium bisulphite … %

03 · GHS classification

Sodium hydrogensulphite … % hazard classification

Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.

Sodium hydrogensulphite … % pictograms and signal word

Signal wordWarning

Sodium hydrogensulphite … % hazard class and category

GHS hazard classes Sodium hydrogensulphite… falls into
Hazard class Category From code Pictogram
Acute toxicity - oral GHS chapter 3.1 Category 4 H302 GHS07

Sodium hydrogensulphite … % hazard statements (H-codes)

Hazard statements assigned to Sodium hydrogensulphite…
CodeHazard statement
H302 Harmful if swallowed.

Sodium hydrogensulphite … % supplemental EU statements (EUH)

EU-specific statements assigned to Sodium hydrogensulphite…. They exist only in CLP and have no counterpart in UN GHS.
CodeStatement
EUH031 Contact with acids liberates toxic gas.

This page lists only the codes assigned to Sodium hydrogensulphite…. The full reference lives on the hazard statements hub, the precautionary statements hub and the GHS pictograms hub.

Safety Data Sheet

Getting an SDS for Sodium hydrogensulphite…

A Safety Data Sheet is written for a product, not for a substance: the supplier of the grade you actually buy issues it, so two suppliers of Sodium hydrogensulphit… issue two different sheets. That is why there is no single authoritative SDS for a substance to download — what there is, is the job of collecting the sheets for the products you hold and keeping them current as suppliers revise them.

04 · Precautionary statements

Sodium hydrogensulphite … % precautionary statements

CLP Annex VI assigns 4 precautionary statements to Sodium hydrogensulphite…. They are grouped the way a label groups them: what to do before handling, what to do when something has already happened, how to store it and how to dispose of it.

Prevention

What to do before and during handling so the hazard never happens.

Response

What to do once exposure, spillage or fire has already happened.

Reading the notation. is a blank the supplier fills in — not a truncated sentence.· [square brackets] mark a part printed only when it applies.

05 · Names in the regulation

Sodium hydrogensulphite … % name in 23 EU languages

CLP Annex VI Part 3 is published in every language edition of the regulation, and the identification column is written out in each of them. Nothing below is translated by us: each line is the name as that edition prints it. Under Art. 18(2) the substance name from Annex VI is a lawful product identifier, so this is the wording to put on a label going to that market — and where the cell lists several designations, any one of them qualifies.

Language Name in CLP Annex VI Part 3
Bulgarian български натриев хидрогенсулфит … % натриев бисулфит . . . %
Spanish español Hidrogenosulfito de sodio al … % bisulfito de sodio al … %
Czech čeština hydrogensiřičitan sodný… %
Danish dansk natriumhydrogensulfit … % natriumdisulfit . . . %
German Deutsch Natriumhydrogensulfit . . . % Natriumdisulfit . . . %Natriumbisulfit … %Natriumbisulfit . . . %
Estonian eesti naatriumvesiniksulfit … %
Greek ελληνικά όξινο θειώδες νάτριο … % διθειώδες νάτριο . . . %
English English sodium hydrogensulphite … % sodium bisulphite . . . %
French français hydrogénosulfite de sodium % bisulfite de sodium . . %
Croatian hrvatski natrijev hidrogensulfit % natrijev bisulfit . . . %
Italian italiano This edition has a typographic error here. The Italian edition leaves the second designation untranslated: "sodium bisulphite" is the English wording, printed inside the Italian cell. Regulation (EU) 2018/669, OJ L 115, 4.5.2018, p. 79 idrogenosolfito di sodio . . .% sodium bisulphite . . .%
Latvian latviešu nātrija hidrogēnsulfīts … % nātrija bisulfīts … %
Lithuanian lietuvių …% natrio vandenilio sulfitas …% natrio bisulfitas
Hungarian magyar nátrium-hidrogén-szulfit . % nátrium-biszulfit . . . %
Maltese Malti idroġensulfit tas-sodju … % bisulfit tas-sodju. . . %
Dutch Nederlands natriumwaterstofsulfiet … % natriumbisulfiet . . . %
Polish polski wodorosiarczan(IV) sodu … % wodorosiarczyn sodu . . . %
Portuguese português hidrogenossulfito de sódio a ... % bissulfito de sódio a ... %
Romanian română hidrogenosulfit de sodiu ... % bisulfit de sodiu . . . %
Slovak slovenčina hydrogensiričitan sodný... % hydrogensiričitan sodný. . . %
Slovenian slovenščina natrijev hidrogensulfit ... % natrijev bisulfit . . . %
Finnish suomi natriumvetysulfiitti … % natriumbisulfiitti .... %
Swedish svenska natriumvätesulfit ... % natriumbisulfit . . %

One or more lines above are flagged. In those language editions the Regulation as published in the Official Journal prints something that the rest of the same row contradicts — a name belonging to a different entry, or the qualifier of a paired entry. Each flag cites the amending act and the Official Journal page, so the wording can be checked at source. The lines are reproduced as printed, because Art. 18(2) points at Annex VI and not at our reading of it; the note beside each one says what the row’s own EC and CAS numbers identify.

All 23 language editions of Annex VI carry this entry. Irish is the twenty-fourth official EU language and has no line here for a different reason: no consolidated CLP text has ever been published in Irish, so there is no Irish edition of Annex VI to quote a name from. Source: consolidated CLP, CELEX 02008R1272, language editions. © European Union, https://eur-lex.europa.eu — only the electronic Official Journal of the European Union is authentic.

06 · Label elements

Sodium hydrogensulphite … % GHS label elements

Everything CLP Annex VI fixes for Sodium hydrogensulphite…, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.

GHS07 Exclamation mark pictogram

Warning

Sodium hydrogensulphite … %

  • Harmful if swallowed.
  • Contact with acids liberates toxic gas.
  • Do not eat, drink or smoke when using this product.
  • IF SWALLOWED:
  • Call a POISON CENTER/doctor/ if you feel unwell.
  • Rinse mouth.

Supplier name, address and telephone number· Product identifier·Nominal quantity

Need this as an actual label? Open Sodium hydrogensulphite… in the GHS label constructor →

07 · Health hazards

Sodium hydrogensulphite … % health hazards and exposure limits

Sodium hydrogensulphite … % hazard summary

A case of occupational asthma, confirmed by specific inhalation challenge, was reported in which a worker sprinkled dry metabisulfite on potatoes. [Malo JL, Cartier A, Desjardins A. Occupational asthma caused by dry metabisulphite. Thorax 1995 May;50(5); 585-6.] Similar cases have been reported in the wine, laundry, and lobster fishing industries. [Madsen J, Sherson D, Kjoller H, Hansen I, Rasmussen K. Occupational asthma caused by sodium disulphite in Norwegian lobster fishing. Occup Environ Med 2004;61:873-874] Powder is irritating to eyes, nose, and throat and can irritate skin. [CAMEO] See SULFITES.

Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases

Sodium hydrogensulphite … % carcinogenicity classification

Evaluation: There is inadequate evidence for the carcinogenicity in humans of sulfur dioxide, sulfites, bisulfites and metabisulfites. There is limited evidence for the carcinogenicity in experimental animals of sulfur dioxide. There is inadequate evidence for the carcinogenicity in experimental animals of sulfites, bisulfites and metabisulfites. Overall evaluation: Sulfur dioxide, sulfites, bisulfites and metabisulfites are not classifiable as to their carcinogenicity to humans (Group 3).

Source: Hazardous Substances Data Bank (HSDB)

An IARC group and a CLP classification answer different questions. IARC judges whether the evidence for cancer in humans is strong enough; CLP Annex VI is the legally binding EU classification. A substance can carry one and not the other.

Sodium hydrogensulphite … % occupational exposure limits

US occupational exposure limits reported for Sodium hydrogensulphite…. PEL is enforceable (OSHA), REL is a recommendation (NIOSH), IDLH is the concentration at which escape becomes impossible without injury.
Limit Value Source
PEL none See Appendix G The National Institute for Occupational Safety and Health (NIOSH)
REL 5 mg/m³ Occupational Safety and Health Administration (OSHA)
REL TWA 5 mg/m3 The National Institute for Occupational Safety and Health (NIOSH)
IDLH N.D. The National Institute for Occupational Safety and Health (NIOSH)

These are United States values. The European Union sets its own indicative and binding limits, and the figure that applies at a given workplace is the one in the local regulation — not the one shown here.

08 · Physical and chemical properties

Sodium hydrogensulphite … % properties

Every value is shown with the conditions it was measured under and the source it came from. Where sources disagree, all values are listed rather than one being picked — the difference is usually a different form of the substance, not an error.

Sodium hydrogensulphite … % boiling point

Property Value Conditions Source
Boiling point 104 °C (219.2 °F) ICSC
100 °C (212 °F) above this value, at 760 mmHg CAMEO
Decomposes decomposes NIOSH

Sodium hydrogensulphite … % melting point

Property Value Conditions Source
Melting point 0 °C (32 °F) below this value CAMEO
Decomposes decomposes HSDB

Sodium hydrogensulphite … % density

Property Value Conditions Source
Density 1.48 g/cm³ HSDB
1.48 g/cm³ at 20 °C CAMEO

Sodium hydrogensulphite … % solubility

Property Value Conditions Source
Solubility Sol in 3.5 parts cold water, in 2 parts boiling water, in about 70 parts alcohol. HSDB
29% NIOSH
29 % (NIOSH, 2024) CAMEO

Sodium hydrogensulphite … % vapor pressure

Property Value Conditions Source
Vapor pressure 18.0015 mmHg at 20 °C ICSC

Sodium hydrogensulphite … % autoignition temperature

Property Value Conditions Source
Autoignition temperature Not flammable (USCG, 1999) CAMEO

Sodium hydrogensulphite … % lower explosive limit (LEL)

Property Value Conditions Source
Lower explosive limit (LEL) Noncombustible Solid NIOSH

Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.

09 · Handling and storage

Sodium hydrogensulphite … % storage and handling

Sodium hydrogensulphite … % safe storage

Separated from acids, strong oxidants and food and feedstuffs. Well closed.

Source: ILO-WHO International Chemical Safety Cards (ICSCs)

Sodium hydrogensulphite … % storage conditions

KEEP WELL CLOSED & IN A COOL PLACE.

Source: Hazardous Substances Data Bank (HSDB)

Sodium hydrogensulphite … % incompatible materials

BISULFITE OF COMMERCE CONSISTS CHIEFLY OF SODIUM METABISULFITE, INCOMPATIBLE WITH ACIDS, OXIDIZERS.

Source: Hazardous Substances Data Bank (HSDB)

Sodium hydrogensulphite … % reactivity

SODIUM BISULFITE is a reducing agent. Emits highly toxic gaseous sulfur dioxide gas when heated to decomposition or on contact with mineral acids [Sax, 9th ed., 1996, p. 2949].

Source: CAMEO Chemicals

Planning storage for a mix of chemicals? Check Sodium hydrogensulphite… in the storage compatibility matrix →

10 · Questions

Sodium hydrogensulphite … % — frequently asked questions

What is the CAS number of Sodium hydrogensulphite … %?

The CAS number of Sodium hydrogensulphite … % is 7631-90-5. Its EC number is 231-548-0.

What does a Sodium hydrogensulphite … % label have to show?

Under CLP Annex VI the label for Sodium hydrogensulphite … % carries the pictogram Exclamation mark and the signal word is Warning.

Is Sodium hydrogensulphite … % flammable?

CLP Annex VI assigns Sodium hydrogensulphite … % no flammability hazard class. That is not a statement that it cannot burn: the harmonised list only records the hazards that were assessed for it.

Is Sodium hydrogensulphite … % a carcinogen?

CLP Annex VI records no harmonised carcinogenicity classification for Sodium hydrogensulphite … %. Annex VI is a list of agreed classifications, not a list of substances found safe, so this is an absence of a classification rather than a clean bill of health.

What is the exposure limit for Sodium hydrogensulphite … %?

The US occupational exposure limit reported for Sodium hydrogensulphite … % is none See Appendix G (The National Institute for Occupational Safety and Health (NIOSH)). Limits differ by country: the EU sets its own indicative and binding values, and the figure that applies at a given workplace is the one in the local regulation.

What is the boiling point of Sodium hydrogensulphite … %?

The boiling point reported for Sodium hydrogensulphite … % is 104 °C (219.2 °F) (ICSC).

What is the melting point of Sodium hydrogensulphite … %?

The melting point reported for Sodium hydrogensulphite … % is 0 °C (32 °F), below this value (CAMEO).

How should Sodium hydrogensulphite … % be stored?

KEEP WELL CLOSED & IN A COOL PLACE. (Hazardous Substances Data Bank (HSDB))

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