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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

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Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

Phosphorus pentachloride decomposes on contact with water/moisture to form phosphoric acid and hydrochloric acid. The evaluation of short-term toxicity to aquatic invertebrates is conducted with the approach of weight of evidence considering one study about hydrochloric acid (EC50 48h is pH= 5.3, equivalent to 0.492 mg/l of HCl) and one study about phosphoric acid (EC50 48h> 376 mg/l). To extrapolate the value for EC50 48h related to PCl5 precautionary principle the lower value of EC50 48h considering values of HCl and H3PO4 is chosen: the value related to hydrochloric acid is so preferred to phosphoric acid. EC50 48h for Daphnia magna was found to be pH 5.3,equivalent to 0.492 mg/l of HCl.

Considering the stoichiometry of hydrolysis reaction of PCl5 (PCl5 +4H2O-> H3PO4 +5HCl) this concentration of HCl is calculated to be equivalent to 0.56 mg/l of PCl5.

In the same manner (using approach of weight of evidence) the evaluation of short-term toxicity to aquatic algae and cyanobacteria is conducted considering one study about hydrochloric acid (EC50 72h growth rate is pH= 5.3, equivalent to 0.492 mg/l of HCl and NOEC 72h growth rate and biomass is pH= 6, equivalent to 0.097 mg/l of HCl) and one study about phosphoric acid (EC50 72h growth rate= 77.9 mg/l). To extrapolate EC50 72h and NOEC 72h related to PCl5 precautionary principle the lower value of EC50 72h growth rate considering values of HCl and H3PO4 is chosen: the value related to hydrochloric acid is so preferred to phosphoric acid. The growth rate is preferred to biomass because it is less precautionary but more realistic. EC50 72 h growth rate for Selenastrum capricornutum was reported to pH= 5.3 equivalent to 0.492 mg/l of HCl and NOEC 72 h growth rate and biomass was reported to be pH= 6 equivalent to 0.097 mg/l of HCl (See SIDS Hydrogen Chloride 2002). Considering the stoichiometry of hydrolysis reaction of PCl5 (PCl5 +4H2O-> H3PO4 +5HCl) these values of HCl are equivalent to EC50 72h (growth rate) = 0.56 mg/l and NOEC 72 h (growth rate and biomass)=0.11 mg/l for PCl5.