Diammonium [[N,N'-ethylenebis[N-(carboxymethyl)glycinato]](4-)-N,N',O,O',ON,ON']hydroxyferrate(2-)

Bioaccumulation: aquatic / sediment

Administrative data

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Acceptable, well documented publication

Data source

Reference

Reference 1

Reference Type:

publication

Title:

A critical comparison of two bioconcentration test methods

Author:

Bishop WE, Maki AW

Year:

1980

Bibliographic source:

Proc. 3rd. Ann. Symp. on Aquatic Toxicity, Eaton JG, Parrish PR, Bionomics, and Hendricks AC, ASTM STP 707: 61-77

Reference 2

Reference Type:

secondary source

Title:

European Union Risk Assessment Report, EDETIC ACID (EDTA), CAS No: 60-00-4, EINECS No: 200-449-4, RISK ASSESSMENT. Final Report

Author:

EU Risk Assessment

Year:

2004

Bibliographic source:

European Chemicals Bureau

Reference 3

Reference Type:

secondary source

Title:

European Union Risk Assessment Report, tetrasodium ethylenediaminetetraacetate (Na4EDTA), CAS No: 64-02-8, EINECS No: 200-573-9, RISK ASSESSMENT. Final Report

Author:

EU Risk Assessment

Year:

2004

Bibliographic source:

European Chemicals Bureau

Materials and methods

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

Test material

Test material information

Constituent 1

Reference substance name:

Tetrasodium ethylenediaminetetraacetate

EC Number:

200-573-9

EC Name:

Tetrasodium ethylenediaminetetraacetate

Cas Number:

64-02-8

Molecular formula:

C10H16N2O8.4Na

IUPAC Name:

tetrasodium 2,2',2'',2'''-(ethane-1,2-diyldinitrilo)tetraacetate

Details on test material:

Ethylenediaminetetraacetic acid (EDTA), tetrasodium salt
Specific activity 237 uCi/mg, labeled at the acetate group methyl carbon position
Purity: >= 98 % (TLC)

Radiolabelling:

yes

Test organisms

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/litre (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.

Study design

Route of exposure:

aqueous

Test type:

flow-through

Water / sediment media type:

natural water: freshwater

Total exposure / uptake duration:

28 d

Test conditions

Hardness:

total hardness of 120 mg/litre (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-litre, all-glass aquaria fitted with removable glass covers.
A standpipe was used to maintain the water volume in the aquaria at 30 litres.
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 litres/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

Results and discussion

Bioaccumulation factor

Bioaccumulation factor 1

Type:

BCF

Value:

ca. 1.8

Basis:

whole body w.w.

Time of plateau:

28 d

Calculation basis:

steady state

Remarks on result:

other: Conc.in environment / dose:0.08 mg/L

Bioaccumulation factor 2

Type:

BCF

Value:

ca. 1.1

Basis:

whole body w.w.

Time of plateau:

28 d

Calculation basis:

steady state

Remarks on result:

other: Conc.in environment / dose:0.76 mg/L

Depuration

Elimination:

yes

Any other information on results incl. tables

RS-Freetext:
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/litre, 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/litre, approximately 81 percent of the accumulated 14C residues were eliminated within 336 h, for fish exposed  
to 0.08 mg/litre, 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.