Registration Dossier

Administrative data

Description of key information

Thiophosphoryl trichloride has a pH = 1.7 at 23°C (10% aqueous solution). According Annex Regulation (EC) No 1272/2008 Annex VII a skin irritation/corrosion and eye irritation study does not need to be conducted, as the available information indicates that the criteria are met for a classification as corrosive to the skin and irritating to the eyes. Thiophosphoryl trichloride hydrolyses in aqueous medium rapidly. After 2.5 h as main components S=P(OH)2Cl and S=P(OH)3 and minor amounts of O=P(OH)2Cl and H3PO4 were found. After 9 hours as main component S=P(OH)3 and minor amounts of O=P(OH)2Cl and H3PO4 were detected. Due to analytical limitations of the method used, hydrogen chloride can not be detected, but the formation of HCl is predicted based on the stoichiometry of the hydrolysis reaction. Phosphoric acid and hydrogen chloride are strong acids and according Regulation (EC) No 1272/2008 Annex VI Table 3.2 hydrogen chloride is corrosive (C; R35) as well as phosphoric acid (C; R34), (C > 25%). Therefore according REACH Annex VII + VIII column 2 a study for skin and eye corrosion does not need to be conducted. 
In a skin irritation study from a secondary source thiophosphoryl trichloride was corrosive (see discussion).

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (corrosive)

Eye irritation

Endpoint conclusion
Endpoint conclusion:
no study available

Respiratory irritation

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

Skin irritation

Liquid test material is introduced under a 1.5 x 1.5 inch 12-ply gauze patch secured in place by two strips of adhesive tape and additonally the trunk is loosely wrapped with an impervious material for 4 hours. After 4 hour of exposure the patches were removed and the resulting reactions are evaluated. Afterwards the test sites are washed. Readings are again made at 24 and 48 hours after application. At all time points severe erythema (score 4) and slight eschar formation in combination with severe edema (score 4) were observed . Therefore thiophosphoryl trichloride was evaluated to be corrosive (Rhone-Poulenc Inc 1972).

Eye irritation

There is no study available which investigates the possible eye irritation property, However, according to ANNEX VII chapter 8.2 column 2 specific rules for adaption of column 1 in Regulation (EC) No. 1907/2006 (REACH) such a study needs not to be performed because there is information available that indicates that the criteria are met for classification as corrosive to the skin.

Respiratory irritation

Strong respiration irritational effects were reported in the handbook of Sax, Dangerous Properties of Industrial Materials, 7th ed., Van Nostrand Reinhold Company, New York,p. 3261.


Effects on skin irritation/corrosion: corrosive

Justification for classification or non-classification

Based on the available data it is proposed to allocate thiophosphoryl trichloride in Category 1B for corrosive substances (H314).

In addition, strong respiration irritational effects were reported in the handbook of Sax, Dangerous Properties of Industrial Materials, 7th ed., Van Nostrand Reinhold Company, New York, p. 3261. Therefore Xi, R 37 (GHS: STOT SE 3, H335) is applicable.