Trisodium hydrogen ethylenediaminetetraacetate

Bioaccumulation: aquatic / sediment

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Principles of method if other than guideline:

The study was conducted according to the methods described by Branson DR, Blau GE, Alexander HC, and Neely WB (1975). Transactions of the American Fisheries Society, Vol. 104, No. 4: 785-792

GLP compliance:

no

Radiolabelling:

yes

Test organisms (species):

Lepomis macrochirus

Details on test organisms:

Juvenile bluegill, Lepomis macrochirus, having an average wet weight of 0.49 g and a standard length ranging from 3.0 to 5.1 cm, were obtained from a commercial hatchery and maintained under laboratory conditions for a minimum of 2 weeks prior to testing. The fish were held in continuously flowing, carbon-filtered well water having a total hardness of 120 mg/L (as calcium carbonate). The fish were fed frozen brine shrimp twice daily. This was occasionally supplemented with feedings of live Daphnia. A 12-h photoperiod was maintained in the holding facilities.

Route of exposure:

aqueous

Test type:

flow-through

Water / sediment media type:

natural water: freshwater

Total exposure / uptake duration:

28 d

Hardness:

total hardness of 120 mg/L (as calcium carbonate)

Test temperature:

21 °C

pH:

7.4

Dissolved oxygen:

near saturation

Details on test conditions:

The bioconcentration test system was based on that described by Branson et al..
The test chambers were 37-L, all-glass aquaria fitted with removable glass covers.
A standpipe was used to maintain the water volume in the aquaria at 30 L.
The tank effluents were collected in a common drain and filtered through activated carbon prior to their disposal.
A combination of incandescent and fluorescent lighting was controlled by an automatic timer to provide a 12 h photoperiod simulating dusk and dawn with graduating intensities.

The system provided a daylight intensity of approximately 350-550 cd (200-300 footcandles).
A 1 L proportional diluter was modified to deliver two concentrations of the test material.
A peristaltic pump or a multichannel syringe pump was used to meter the stock solutions directly into the diluter mixing chambers.
The entire diluter assembly was contained within a stainless steel housing to minimize the possibility of 14C contamination. All tests were conducted at 21 ± 2 °C in carbon-filtered well water.
A flow rate of 10 L/h, with a 95 percent replacement time of approximately 9 h, was sufficient to maintain the dissolved oxygen levels at greater than 60 percent of saturation.

Nominal and measured concentrations:

0.76 and 0.08 mg/L

Conc. / dose:

0.08 mg/L

Type:

BCF

Value:

ca. 1.8 dimensionless

Basis:

whole body w.w.

Time of plateau:

28 d

Calculation basis:

steady state

Remarks on result:

other: Conc. in environment

Conc. / dose:

0.076 mg/L

Type:

BCF

Value:

ca. 1.1 dimensionless

Basis:

whole body w.w.

Time of plateau:

28 d

Calculation basis:

steady state

Remarks on result:

other: Conc. in environment

Elimination:

yes

The measured concentrations of the test compound averaged approximately 80 percent of the nominal values.

There was no substantial difference in measured concentrations during the kinetic (Cwk) and the plateau (Cwp) exposures; the coefficient of  variation was less than 10 percent in all cases.

28-Day (Plateau) Method

-----------------------

At exposures of 0.76 and 0.08 mg/L, 14C-EDTA exhibited an extremely low bioconcentration potential. Not until 672 h of continuous exposure did the EDTA concentrations in fish exceed those in the water. The plateau BCF values for EDTA were approximately 1.1 at 0.76 mg/L and 1.8  at 0.08 mg/L, respectively and were independent of the exposure concentration for the range of values tested.

After the transfer to clean water, there was an apparent difference between the two exposure levels in the rate of elimination of 14C activity.

For fish exposed to 0.76 mg/L, approximately 81 percent of the accumulated 14C residues were eliminated within 336 h, for fish exposed  to 0.08 mg/L, only 60 percent of the accumulated 14C residues had  been eliminated within a comparable time.

5-Day (Kinetic) Method

----------------------

The rate constants calculated for 14C-EDTA were independent of the  exposure concentrations, although the higher-level exposure may have been  clearing somewhat faster. The projected equilibrium BCF values were similar to those observed in the plateau test and, again, serve to emphasize the extremely low bioconcentration potential of EDTA.

Reference 2

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

Refer to the Analogue Approach Justification document provided in Section 13.

Reason / purpose for cross-reference:

read-across source

Conc. / dose:

0.08 mg/L

Type:

BCF

Value:

ca. 1.8 dimensionless

Basis:

whole body w.w.

Time of plateau:

28 d

Calculation basis:

steady state

Remarks on result:

other: Conc. in the environment

Conc. / dose:

0.076 mg/L

Type:

BCF

Value:

ca. 1.1 dimensionless

Basis:

whole body w.w.

Time of plateau:

28 d

Calculation basis:

steady state

Remarks on result:

other: Conc. in the environment

Description of key information

Trisodium hydrogen EDTA (CAS 150-38-9) has a low potential for bioaccumulation.

Additional information

Since no studies investigating the bioaccumulation potential of trisodium hydrogen EDTA (CAS 150-38-9) are available, in accordance to Regulation (EC) No 1907/2006 Annex XI, 1.5 a read-across to a structurally related EDTA species was conducted. This read-across is justified in detail in the overall summary (IUCLID Section 6.1) and within the analogue justification in IUCLID Section 13.

One experimental study is available investigating the bioaccumulation potential of Tetrasodium EDTA (CAS 64-02-8). The study was not conducted according to an internationally accepted guideline but the method is further described by Branson et al. (1975). Juvenile fish (Lepomis macrochirus) were exposed under flow-through conditions to radiolabeled test item at concentrations of 0.76 and 0.08 mg/L, respectively. Fish and water samples were periodically collected for 14C-analysis. The duration of the uptake phase for the kinetic tests was arbitrarily selected as 120 h (5 days). After 120 h, some of the remaining fish were transferred to the depuration tanks, and the clearance of the compound was monitored. The uptake phase was continued for 672 h (28 days) for the plateau tests. Samples collected at 48 and 120 h were designated as the initial plateau samples. Subsequent fish samples were collected at least once a week. Following the 28-day exposure, all the remaining fish were transferred to the depuration tanks in order to investigate the elimination process of the substance. During the study approximately the recovery rate of the nominal concentrations in the test vessels was 80%.
For the 28 d plateau method, negligible potential for bioaccumulation was recorded in fish. The BCF values ranged from 1.1 at 0.76 mg/L to 1.8 at 0.08 mg/L. A slight difference in depuration was recorded after transfer to the depuration vessels. Whereas approximately 81% of the accumulated 14C-EDTA was eliminated after 336 h only 60% was eliminated within a comparable time at 0.08 mg/L.
Thus, in conclusion EDTA has a negligible potential for bioaccumulation. This is also supported by the very low log Pow of -3.8.