Tetrakis(hydroxymethyl)phosphonium sulphate(2:1)

Short-term toxicity to aquatic invertebrates

Description of key information

EPA OPP 72-2, OECD Guideline 202, GLP, key study, validity 1:
48h-EC50 (Daphnia magna) = 11.3 mg/L (measured, as main ingredient)
ISO Guideline 14669 (draft 1990), GLP, key study, validity 2:
48h-LC50 (Acartia tonsa) = 0.45 mg/L (nominal, as main ingredient)
In conclusion, THPS is very toxic to aquatic invertebrates.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

11.3 mg/L

Marine water invertebrates

Marine water invertebrates

Effect concentration:

0.45 mg/L

Additional information

Eight studies are available to assess the short-term toxicity of the active substance THPS to aquatic invertebrates. These studies were performed on the THPS in solution in static, semi-static or flow-through conditions, with reshwater and marine species. The relevant results were expressed as main ingredient (100% active substance).

 

There are two studies of reliability 1 and 2 on the freshwater species Daphnia magna (Jenkins, 1991c; Douglas, 1985b) and six studies of reliability 1 and 2 on several marine species (Torp, 1994; Altin, 1994; Boeri, 1995b; Boeri, 1995c; Douglas, 1986; Sewell, 2004).

 

For freshwater species Daphnia magna, the study of best reliability and lowest EC50 value has been defined as key study (Jenkins, 1991c).

For marine species, the most sensitive species is Acartia tonsa. Three studies of reliability 2 are available on this species and show similar results (Torp, 1994; Altin, 1994; Sewell, 2004). The study of lowest L(E)C50 value and owned by Rhodia has been defined as key study (Torp, 1994). Even if the LC50 value of this study (=0.45 mg/L) is slightly greater than the LC50 value of the Sewell (2004) study (=0.29 mg/L), we are more confident on the test substance, that should be closer to the reference substance.

Results are expressed in the table below (as main ingredient):

Test method	Species	Endpoint / Type of test	Exposure	Reliability	Flag	Results (L(E)C50 (95% CL), mg/L)	Reference
EPA OPP 72-2 and OECD Guideline 202	Daphnia magna (freshwater species)	Immobilisation / Acute	Static, 48h	1	KS	11.3 (9.1-13.6)	Jenkins, 1991c
OECD Guideline 202	Daphnia magna (freshwater species)	Immobilisation / Acute	Static, 48h	2	SS	14.3 (12.0-16.5)	Douglas, 1985b
ISO 14669 (draft 1990)	Acartia tonsa (marine species)	Mortality / Acute	Static, 48h	2	KS	0.45 (0.38-0.54)	Torp, 1994
ISO 14669 (draft 1990)	Acartia tonsa (marine species)	Mortality / Acute	Static, 48h	2	SS	0.98 (0.83-1.13)	Altin, 1994
ISO 14669 (1999)	Acartia tonsa (marine species)	Mortality / Acute	Static, 48h	2	SS	0.29 (0.23-0.38)	Sewell, 2004*
EPA OPP 72-3	Crassostrea virginica (marine species)	Shell growth / Acute	Flow-through, 96h	1	SS	1.6 (1.3-1.9)	Boeri, 1995b
EPA OPP 72-3	Mysidopsis bahia (marine species)	Mortality, Shell growth / Acute	Flow-through, 96h	1	SS	7.30 (6.03-9.61)	Boeri, 1995c
Ministry of Agriculture, Fisheries and Food, UK	Crangon crangon (marine species)	Mortality / Acute	Semi-static, 96h	2	SS	253 (190-337)	Douglas, 1986

*This study is not owned by Solvay, the test report is available on the US EPA web site at EPA/OPPT/Toxic Substance Control Act Section 8(e), the test substance was not manufactured by Solvay, THPS main ingredient content is 75 %.

According to the key studies, THPS is considered harmful to freshwater species Daphnia magna (48-EC50 = 11.3 mg/L) and very toxic to marine species Acartia tonsa (48h-LC50 = 0.45 mg/L). Therefore, it can be concluded that THPS is very toxic to aquatic invertebrates