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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Description of key information

The test substance is classified as highly corrosive according to Directive 67/548/EEC, Annex I, therefore testing is not required.

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (corrosive)

Eye irritation

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (irritating)

Additional information

The test substance is classified as highly corrosive (R35) according to Directive 67/548/EEC, Annex I. Therefore, the testing of irritant properties is not required according to Regulation (EC) No1907/2006, Annex VIII, column 2.

SOCl2 is hydrolyzed rapidly and completely by water in an exothermic reaction with formation of HCl and SO2. Therefore the toxicity of the hydroysis products(HCl and SO2) is also considered and compared with thionyl dichloride.

There are several studies with reliability 1 or 2 available for HCl concerning skin irritation/corrosion (OECD SIDS for HCl). Concentrations above 3.3% cause irritation and concentrations above 17% cause corrosion in animal studies.

According to Annex I of the Directive 67/548/EEC, hydrochloric acid is classified as C; R34: Corrosive; Causes severe burns for concentration C >= 25% and Xi; R37: Irritation; Irritating to the respiratory system for concentration 10% <= C < 25%.

There are several studies with reliability 1 or 2 available (OECD SIDS for HCl) concerning eye irritation. Concentrations above 3.3

% cause irritation, and higher concentrations or prolonged exposure cause damage of the tissue in the animal studies. Conflicting results may be observed in eye irritation studies depending on the protocol used. The severity of the effects is influenced by the exposure amount, concentration, duration and the treatment, because tears induce buffering and diluting effects.

For SO2 animal studies are not available, scientifically not justified and technically not feasible according standard protocols due to technical reasons because SO2 is a gaseous substance at room temperature under normal pressure. In the acute inhalation study with thionyl dichloride (Pauluhn 1986) a strong irritation potential to the respiratory tract was reported. In the acute inhalation study from Pauluhn ) 1991, a local damage of the eyes (opacity of the cornea) was reported for SO2.

In conclusion, the available data for HCl and SO2 indicate a strong irritation/corrosive potential.


Justification for selection of skin irritation / corrosion endpoint:
A not assignable effect level from a secondary source for thionyl chloride (SOCl2) is available.
SOCl2 is hydrolyzed rapidly and completely by water in an exothermic reaction with formation of HCl and SO2. Therfore the toxicity of the hydroysis products is also considered.

Justification for selection of eye irritation endpoint:
A not assignable effect level from a secondary source for thionyl chloride (SOCl2) is available.
SOCl2 is hydrolyzed rapidly and completely by water in an exothermic reaction with formation of HCl and SO2. Therfore the toxicity of the hydroysis products is also considered.

Effects on skin irritation/corrosion: highly corrosive

Effects on eye irritation: highly corrosive

Effects on respiratory irritation: highly irritating

Justification for classification or non-classification

Classified as highly corrosive R35 according to the criteria of DSD and as Skin Corr. Cat. 1A according to the criteria of CLP.