L-Aspartic acid, N,N'-1,2-ethanediylbis-

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

Not P/vP

[S,S]-EDDS acid and its trisodium salt have been shown to be readily biodegradable - with biodegradation rates of at least 75% within 28 days - in the modified Sturm test (Guekens, 1993a; Schowanek et al. 1997), unacclimated river water die-away test (Jaworska et al. 1999; Schowanek et al. 1997), semi-continuous activated sludge test (Schowanek et al. 1997) and the batch-activated sludge tests with acclimated and unacclimated sludge (Schowanek et al. 1997). Where relevant, these tests were conducted in line with corresponding OECD Guidelines.

Not B/vB

In a GLP study conducted according to OECD Guideline 107, the log Pow of EDDS acid was calculated to be <-1.4 at 23oC (Gair et al. 2002).

Not T

In a GLP study conducted according to OECD Guideline 210, the effect on hatching, survival and the occurrence of egg and larval malformations following exposure to trisodium EDDS in the freshwater Zebra fish, Brachydanio rerio, was investigated. At nominal concentrations of 348 mg/L and above, growth (measured as dry weight) was significantly retarded for the surviving fish, but no effects on growth were seen at 196 mg/L (considered the 30-d NOEC for such effects) and below. The 30-d NOEC for mortality and condition was 61 mg/L.

In a GLP study, similar to OECD Guideline 211 and EU Method C.20, the 21-d NOEC for trisodium EDDS for effects on reproduction, survival, condition and size to Daphnia magna in freshwater was 32 mg/L.

In good-quality NCI studies, conducted according to a protocol similar to OECD Guideline 451, trisodium ethylenediaminetetraacetate (EDTA) showed no evidence of carcinogenic potential when fed to rats and mice in the diet for 2 years at up to 7500 ppm (about 375 and 1125 mg/kg bw/day, respectively) (NCI, 1977). Based on their structural similarity, it is expected that EDDS acid is also unlikely to induce tumorigenicity following long-term oral exposure at comparable doses.

In a GLP study, conducted according to EPA Guidelines (OPPTS 870.3700), Maternal toxicity, evident as soft feces and a slight reduction in body weight gain, was seen at 1000 mg/kg bw/day (the highest tested dose), therefore 400 mg/kg bw/day considered the study NOAEL (Denny, 1996e).

In a GLP study conducted according to OECD Guideline 471, EDDS acid showed no evidence of mutagenic potential when tested at up to 5 mg/plate in an(Ames test) both in the presence and absence of (S9) (Thompson, 2002). On the related material, trisodium EDDS also showed no mutagenic activity in Ames tests when tested at up to 5 mg/plate , with and without S9 (Jones et al. 1989; San and Wyman, 1993). In a GLP study, trisodium EDDS showed no evidence of mutagenic potential at the tk locus in mouse lymphoma L5178Y tk+/- cells in an in vitro mammalian cell mutation assay when tested at up to about 5 mg/mL, with and without S9 (Bigger and Clarke, 1993). In a in vivo GLP study equivalent to OECD Guideline 475, trisodium EDDS showed no evidence of induction of numerical or structural chromosome aberrations when administered as a single oral dose at up to 2000 mg/kg bw in a bone marrow cytogenetic assay in male and female rats (Putman, 1994).Overall, it can be concluded that EDDS acid and its trisodium salt are not genotoxic.

In a GLP study conducted according to OECD Guideline 408 (available at the time), a 90-d NOAEL of 300 mg/kg bw/day was established for the related material trisodium EDDS based on a reduction in body weight gain and single cell death and fatty infiltration in the pancreas seen in rats at 700 mg/kg bw/day and above following repeated dietary administration (Dotti et al. 1995).

In a GLP study designed to assess toxicity and mineral balance, no adverse effects were observed when trisodium EDDS was given to male rats in the diet for 28 days at up to 400 mg/kg bw/day, considered the study NOAEL. A dose-related and statistically significant increase in the urinary excretion of zinc was observed at all tested doses (50 mg/kg bw/day and above; considered the study LOEL), which was compensated for by a decrease in faecal zinc excretion (measured only in the two highest dose groups) so that the overall total excretion of zinc was unaltered (Dotti, 1995).

In a GLP study, trisodium EDDS showed no evidence of toxicity when fed in the diet to male rats for 14 days at up to 1250 mg/kg bw/day, considered the study NOEL (Dotti and Wilson, 1996).

In a 14-day dietary study, trisodium EDDS exhibited toxicity at 2500 mg/kg bw/day and above in male and female rats, seen as loss of body weight, reduced food and water consumption, diarrhoea and hunched posture. The study NOAEL is therefore 500 mg/kg bw/day (Dotti, 1993).