Human health hazard profile

• Author: Clemm, Christan; Löw, Clara; Baron, Yifaat; Moch, Katja; Möller, Martin; Köhler, Andreas R; Gensch, Carl-Otto; Deubzer, Otmar
• Pages: 24-27

RoHS Annex II Dossier, final

Five cobalt salts

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3. HUMAN HEALTH HAZARD PROFILE

According to an ECHA report,47 which was prepared to support the assessment of remaining

cancer risks related to the industrial use of cobalt salts in the context of chemical risk management

procedures under REACH, the divalent cobalt cation (Co2+) moiety is considered to constitute the

critical entity of the five cobalt salts and being responsible for systemic toxicity. In consequence,

the classification of the five cobalt salts in Annex VI of the CLP regulation is identical.

As for the counter ions of the cobalt salts (i.e. sulphate, nitrate, chloride, acetate, and carbonate),

ECHA (2018) summarises that the combination of released ions (i.e. both the cobalt (II) ion and the

anion) is expected to be responsible for local toxicity by exposure to lungs or skin.

3.1. Critical endpoints

The cobalt salts are classified for the following human health hazards:

•CMR substances (carcinogenic and toxic for reproduction) and therefore recognised as

substances of very high concern. Furthermore, they are recognised as being mutagenic (H341 -

Suspected of causing genetic defects).

The CMR properties are explained in more detail further below.

•They are recognised skin and respiratory sensitizing chemicals: H317 - May cause an allergic

skin reaction and H334 - May cause allergy or asthma symptoms or breathing difficulties if

inhaled.

•They are recognised as being acute toxic (category 4: H302 - Harmful if swallowed).

In the following, the consideration on carcinogenicity and mutagenicity are summarised from the

ECHA report48 as it is understood to be the most recent compilation on these critical endpoints of

the five soluble cobalt salts:

Carcinogenicity

The carcinogenicity classification was allocated because the cobalt salts may cause cancer by

inhalation.

According to ECHA (2017), uncertainties existed on the carcinogenic mode of action, whether the

cobalt salts exhibit a threshold mode of action regarding their carcinogenicity effects - as claimed in

the registration dossiers - or whether they should be considered as non-threshold carcinogens.

An assessment made by DHI49 concluded that due to a lack of identified thresholds and due to

remaining uncertainties regarding the mechanisms involved, the water-soluble cobalt salts are

considered as genotoxic carcinogens and are to be assessed using a non-threshold approach.50

47 ECHA project SR 23 (no year): Support to the assessment of remaining cancer risks related to the industrial use of

cobalt salts in the context of chemical risk management procedures under REACH, Poul Bo Larsen (DHI), Brian

Svend Nielsen (DHI), Mona-Lise Binderup;

https://echa.europa.eu/documents/10162/13563/echa_sr23_project_en.pdf, last viewed 16.07.2018

48 ECHA project SR 23 (no year): Support to the assessment of remaining cancer risks related to the industrial use of

cobalt salts in the context of chemical risk management procedures under REACH, Poul Bo Larsen (DHI), Brian

Svend Nielsen (DHI), Mona-Lise Binderup;

https://echa.europa.eu/documents/10162/13563/echa_sr23_project_en.pdf, last viewed 16.07.2018