Substance Information

Substance Infocard


Chlorine dioxide generated from sodium chlorite by acidification

Help Substance identity

The ‘Substance identity’ section is calculated from substance identification information from all ECHA databases. The substance identifiers displayed in the InfoCard are the best available substance name, EC number, CAS number and/or the molecular and structural formulas.

Some substance identifiers may have been claimed confidential, or may not have been provided, and therefore not be displayed.

EC (European Community) Number

The EC Number is the numerical identifier for substances in the EC Inventory. The EC Inventory is a combination of three independent European lists of substances from the previous EU chemicals regulatory frameworks (EINECS, ELINCS and the NLP-list). More information about the EC Inventory can be found here.

If the substance was not covered by the EC Inventory, ECHA attributes a list number in the same format, starting with the numbers 6, 7, 8 or 9.

The EC or list number is the primary substance identifier used by ECHA.

CAS (Chemical Abstract Service) registry number

The CAS number is the substance numerical identifier assigned by the Chemical Abstracts Service, a division of the American Chemical Society, to substances registered in the CAS registry database. A substance identified primarily by an EC or list number may be linked with more than one CAS number, or with CAS numbers that have been deleted. More information about CAS and the CAS registry can be found here.

Molecular formula

The molecular formula identifies each type of element by its chemical symbol and identifies the number of atoms of each element found in one discrete molecule of the substance. This information is only displayed if the substance is well–defined, its identity is not claimed confidential and there is sufficient information available in ECHA’s databases for ECHA’s algorithms to generate a molecular structure.

Molecular structure

The molecular structure is based on structures generated from information available in ECHA’s databases. If generated, an InChI string will also be generated and made available for searching. This information is only displayed if the substance is well-defined, its identity is not claimed confidential and there is sufficient information available in ECHA’s databases for ECHA’s algorithms to generate a molecular structure.

More help available here.

EC / List no.: -

CAS no.: -

Mol. formula:

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Help Hazard classification and labelling

The ‘Hazard classification and labelling’ section shows the hazards of a substance based on the standardised system of statements and pictograms established under the CLP (Classification Labelling and Packaging) Regulation. The CLP Regulation makes sure that the hazards presented by chemicals are clearly communicated to workers and consumers in the European Union. The CLP Regulation uses the UN Global Harmonised System (GHS) and European Union Specific Hazard Statements (EUH).

This section is based on three sources for information (harmonised classification and labelling (CLH), REACH registrations and CLP notifications). The source of the information is mentioned in the introductory sentence of the hazard statements. When information is available in all sources, the first two are displayed as a priority.

Please note:

The purpose of the information provided under this section is to highlight the substance hazardousness in a readable format. It does not represent a new labelling, classification or hazard statement, neither reflect other factors that affect the susceptibility of the effects described, such as duration of exposure or substance concentration (e.g. in case of consumer and professional uses). Other relevant information includes the following:

  • Substances may have impurities and additives that lead to different classifications. If at least one company has indicated that the substance classification is affected by impurities or additives, this will be indicated by an informative sentence. However, substance notifications in the InfoCard are aggregated independently of the impurities and additives.
  • Hazard statements were adapted to improve readability and may not correspond textually to the hazard statements codes description in the European Union Specific Hazard Statements (EUH) or the UN Global Harmonised System (GHS).

To see the full list of notified classifications and to get more information on impurities and additives relevant to classification please consult the C&L Inventory.

More information about Classification and Labelling is available in the Regulations section of ECHA website.

More help available here.

Harmonised classification and labelling (CLH)

Harmonised classification and labelling is a legally binding classification and labelling for a substance, agreed at European Community level. Harmonisation is based on the substance’s physical, toxicological and eco-toxicological hazard assessment.

The ‘Hazard classification’ and labelling section uses the signal word, pictogram(s) and hazard statements of the substance under the harmonised classification and labelling (CLH) as its primary source of information.

If the substance is covered by more than one CLH entry (e.g. disodium tetraborate EC no. 215–540–4, is covered by three harmonisations: 005–011–00–4; 005–011–01–1 and 005–011–02–9), CLH information cannot be displayed in the InfoCard as the difference between the CLH classifications requires manual interpretation or verification. If a substance is classified under multiple CLH entries, a link to the C&L Inventory is provided to allow users to view CLH information associated with the substance and no text is automatically generated for the InfoCard.

It is possible that a harmonisation is introduced through an amendment to the CLP Regulation. In that case, the ATP (Adaptation to Technical Progress) number is displayed.

More info on CLH can be found here.

Classification and labelling under REACH

If available, additional information on classification and labelling (C&L) is derived from REACH registration dossiers submitted by industry. This information has not been reviewed or verified by ECHA, and may change without prior notice. REACH registration dossiers have greater data requirements (such as supporting studies) than do notifications under CLP.

Notifications under the Classification Labelling and Packaging (CLP) Regulation

If no EU harmonised classification and labelling exists and the substance was not registered under REACH, information derived from classification and labelling (C&L) notifications to ECHA under CLP Regulation is displayed under this section. These notifications can be provided by manufacturers, importers and downstream users. ECHA maintains the C&L Inventory, but does not review or verify the accuracy of the information.

Note that for readability purposes, only the pictograms, signal words and hazard statements referred in more than 5% of the notifications under CLP are displayed.

There is no harmonised classification and there are no notified hazards by manufacturers, importers or downstream users for this substance.

Biocidal Uses

This substance is being reviewed for use as a biocide in the EEA and/or Switzerland, for: disinfection, veterinary hygiene, food and animals feeds, drinking water, preservation of fibres, leather, rubber, or polymers, preservation for liquid systems, controlling slimes.

about INFOCARD - Last updated: 26/05/2022 InfoCard

The InfoCard summarises the non-confidential data of a substance held in the databases of the European Chemicals Agency (ECHA). InfoCards are generated automatically based on the data available at the time of generation.

The quality and correctness of the information submitted to ECHA remains the responsibility of the data submitter. The type of uses and classifications may vary between different submissions to ECHA and for a full understanding it is recommended to consult the source data. Information on applicable regulatory frameworks is also automatically generated and may not be complete or up to date. It is the responsibility of the substance manufacturers and importers to consult official publications, e.g. the electronic edition of the Official Journal of the European Union.

InfoCards are updated when new information is available. The date of the last update corresponds to the publication date of the InfoCard and not necessarily to the date in which the update occurred in the source data.

More help available here.

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Key datasets


Regulatory context

Here you can find all of the regulations and regulatory lists in which this substance appears, according to the data available to ECHA. This substance has been found in the following regulatory activities (directly, or inheriting the regulatory context of a parent substance):

BPR - Biocidal Products Regulation
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Substance names and other identifiers

Regulatory process names
Chlorine dioxide generated from sodium chlorite by acidification
Biocidal active substances, Other
Translated names
Aktívny bróm získaný z bromidu sodného elektrolýzou (sk)
Biocidal active substances
Chloordioxide, door middel van aanzuring verkregen uit natriumchloriet (nl)
Biocidal active substances
Chlordioxid genereret fra natriumchlorit ved tilsætning af syre (da)
Biocidal active substances
Chlordioxid, durch Säuerung aus Natriumchlorit hergestellt (de)
Biocidal active substances
Chloro dioksidas, gautas iš natrio chlorito rūgštinant (lt)
Biocidal active substances
Diossido di cloro ottenuto da acidificazione di clorito di sodio (it)
Biocidal active substances
Diossidu tal-kloru ġġenerat minn klorit tas-sodju bl-aċidifikazzjoni (mt)
Biocidal active substances
Dioxid de clor sintetizat din clorit de sodiu prin acidifiere (ro)
Biocidal active substances
Dioxyde de chlore produit par acidification de chlorite de sodium (fr)
Biocidal active substances
Dióxido de cloro generado por acidificación a partir de clorito de sodio (es)
Biocidal active substances
Dióxido de cloro produzido a partir de clorito de sódio por acidificação (pt)
Biocidal active substances
Dwutlenek chloru uzyskany z chlorynu sodu poprzez zakwaszanie (pl)
Biocidal active substances
kloordioksiid, mis saadakse naatriumkloritist hapustamisega (et)
Biocidal active substances
Klordioksid generert fra natriumkloritt ved surgjøring (no)
Biocidal active substances
Klordioxid som framställs genom surgörning av natriumklorit (sv)
Biocidal active substances
Klorov dioksid dobiven iz natrijevog klorita s pomoću zakiseljavanja (hr)
Biocidal active substances
klorov dioksid, pridobljen iz natrijevega klorita z acidifikacijo (sl)
Biocidal active substances
Natriumkloriitista happoa lisäämällä tuotettu klooridioksidi (fi)
Biocidal active substances
No nātrija hlorīta ar paskābināšanu iegūts hlora dioksīds (lv)
Biocidal active substances
Nátrium-kloritból savas kezeléssel előállított klór-dioxid (hu)
Biocidal active substances
Oxid chloričitý připravený okyselením chloritanu sodného (cs)
Biocidal active substances
Διοξείδιο του χλωρίου που παράγεται από χλωριώδες νάτριο με οξίνιση (el)
Biocidal active substances
Хлорен диоксид, генериран от натриев хлорит посредством подкиселяване (bg)
Biocidal active substances
IUPAC names
Chlorine dioxide generated from sodium chlorite by acidification
Biocidal active substances