Phosphoryl trichloride

Endpoint summary

Description of key information

“In water, phosphoryl trichloride hydrolyzes to phosphoric acid and hydrochloric acid with t1/2 < 10 seconds (Riess, 2002): POCl3 + 3 H2O → H3PO4 + 3 HCl” (OECD SIDS for phosphoryl trichloride, 2004).

 

The corresponding pH value of phosphoryl trichloride at 25 °C is approximately 1 (at 5 g/L).

Further testing is not required on scientific grounds and for reasons of animal welfare. However, the available data for phosphoryl trichloride are reported.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Summary of non-standard study; adequate for the purposes of classification

Qualifier:

no guideline followed

Principles of method if other than guideline:

Investigation of the irritant effects of a transient dermal exposure and assessment of the efficacy of decontamination.

GLP compliance:

not specified

Remarks:

: summary report only

Species:

rabbit

Strain:

not specified

Type of coverage:

not specified

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

not required

Duration of treatment / exposure:

60 seconds

Observation period:

Not reported

Number of animals:

Not reported

Irritation parameter:

other: details are not reported

Reversibility:

no data

Remarks on result:

other: signs of severe skin irritation or corrosion were noted

Other effects:

Depending on the decontamination method, the substance is reported to be either a severe irritant or corrosive to skin.

Depending on the decontamination method, the substance is reported to be either a severe irritant or corrosive to skin.

Interpretation of results:

other: corrosive

Conclusions:

Application of phosphoryl trichloride to skin resulted in severe irritation or corrosive effects.

Executive summary:

100 µl of phosphoryl trichloride applied to shaved rabbit skin for 60 seconds resulted in severe skin irritation or corrosive effects.

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

Skin irritation/corrosion:

Phosphoryl trichloride was found to cause corrosive effects in a skin irritation study (Imlay, 1977). Similar effects are reported in studies by Birch (1978) and Molodkina (1973). A study summary (Pauluhn, 1984) reports corrosive effects within 60 seconds of the dermal application of 100 µl phosphoryl trichloride.

Eye irritation:

Severe reactions seen in an eye irritation study (Imlay, 1977) were confirmed in other studies by Birch (1978) and Molodkina (1973).

Respiratory irritation:

Phosphoryl trichloride reacts with water, forming hydrochloric acid and phosphoric acid. Due to this hydrolytic reaction, phosphoryl trichloride is corrosive to the skin, eyes and respiratory tract. The acute toxicity of phosphoryl trichloride following inhalation is high. The 4h-LC50 of phosphoryl trichloride is 48.4 ppm (308 mg/m³) to 11.1 ppm (71 mg/m³) for rats and 52.5 ppm (335 mg/m³) for guinea pigs. Clinical signs included severe respiratory tract irritation, nasal discharge and eye irritation.

Justification for selection of skin irritation / corrosion endpoint:
The study of Pauluhn (1984) reports corrosive effects within 60 seconds of the dermal application of 100 µl phosphoryl trichloride.

Justification for selection of eye irritation endpoint:
Several limited studies reported irritant/corrosive effects on the eyes of rabbits.

Effects on skin irritation/corrosion: corrosive

Effects on eye irritation: irreversible effects on the eye

Effects on respiratory irritation: highly irritating

Justification for classification or non-classification

Phosphoryl trichloride is listed on Annex VI of Regulation (EC) No 1272/2008 with classification as Skin corr. 1A, H314: Causes severe skin burns and eye damage. No change to this classification is proposed.