Diammonium [N,N-bis[2-[bis(carboxymethyl)amino]ethyl]glycinato(5-)]ferrate(2-)

Long-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

adult fish: sub(lethal) effects

Type of information:

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

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study well documented, meets generally accepted scientific principles, acceptable for assessment; however there were no analytical measurements of test solution concentrations.

Justification for type of information:

1. HYPOTHESIS FOR THE ANALOGUE APPROACH

The effect observed for DTPA-H5 during a Long term fish test as published by van Dam is read across to DTPA-Fe(NH4)2. This read across is considered justified because the effects observed will be caused by the DTPA-Fe complex. Ammonium, potassium, sodium, hydrogen are only counter ions needed to neutralize the product and these ions will easily dissociate from the DTPA-Fe complex when evaluated in aquatic ecotoxicity tests under ambient conditions. REPORTING FORMAT FOR THE ANALOGUE APPROACH
[Please provide information for all of the points below. Indicate if further information is included as attachment to the same record, or elsewhere in the dataset (insert links in

Reason / purpose for cross-reference:

read-across source

Qualifier:

no guideline followed

Principles of method if other than guideline:

Adult fish (2 males and three females per tank) were exposed to the test material for 28 days, and reproduction, growth, organ weights, and an enzymatic biomarker were assessed.

GLP compliance:

not specified

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
no data

Analytical monitoring:

no

Details on sampling:

not applicable

Vehicle:

no

Details on test solutions:

The experiment was carried out using a static-renewal regime, whereby 50% of the test solution was replaced daily. Test solutions for each aquarium were prepared daily in a 20-L plastic container using a freshly prepared 5-liter stock solution of 2000 mg/L DTPA. The dilution water used in the experiment was wet laboratory water which was pumped into a 400-liter storage tank and heated to 25 degrees C. The pH of the stock solution and the test solutions was adjusted to approximately 7.4 with 5 M NaOH.

Test organisms (species):

other: Melanotaenia fluviatilis

Details on test organisms:

TEST ORGANISM
- Common name: Crimson-spotted Rainbowfish
- Source: The original M. fluviatilis laboratory stocks were collected from the Murray River, Victoria, Australia in 1990.
- Method of breeding:
- Feeding during test
- Food type: flake food, live and frozen brine shrimp
- Amount: ad libitum (flake food), 5 -ml (brine shrimp)
- Frequency: 2 times daily


ACCLIMATION
- Acclimation period: 1 week
- Acclimation conditions (same as test or not): same as in the test

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

28 d

Post exposure observation period:

Embryos were collected from the exposure aquaria, put into clean water and observed for viability.

Hardness:

not reported

Test temperature:

25 degrees C

pH:

mean pH after renewals = 7.31 (standard error = 0.03)
mean pH prior to renewals = 7.28 (standard error = 0.03)

Dissolved oxygen:

Mean DO in test aquaria = 8.20 (standard error = 0.07)
Mean DO in egg-hatching aquaria = 9.11 (standard error = 0.06)

Salinity:

not applicable

Nominal and measured concentrations:

Nominal concentrations were 0, 1, 10, 100 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass aquaria containing 30 liters of aerated test solution.
- Renewal rate of test solution (frequency/flow rate): 50% renewal (15 liters) daily, except on Day 15, when there was a 100% test solution renewal
- No. of organisms per vessel: 5 (2 males and 3 females)
- No. of vessels per concentration (replicates): 5 replicates
- No. of vessels per control (replicates): 5 replicates


OTHER TEST CONDITIONS
- Adjustment of pH: pH adjusted to 7.4
- Conductivity ranged from 54.6 (control) to 104.7 (100 mg/L) uS/cm


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Reproduction was assessed on Day 0, 6-7, 13-14, 27-28.
At the end of the exposure (Day 28) fish length and weight were measured. Gonad and liver weight were also determined on Day 28 to calculate the liver-somatic index and the gonadal-somatic index. Ethoxyresorufin O-deethylase (EROD) activity was also assessed in fish liver tissue following 28 days of exposure.

Reference substance (positive control):

no

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Details on results:

The only effect observed during the experiment was a 50% inhibition in activity of the hepatic MFO enzyme ethoxyresorufin O-deethylase in female rainbow fish exposed to 100 mg/L DTPA. This effect is biochemical in nature and is not an appropriate endpoint on which to base risk assessment decisions. No effects on condition factor or reproduction were noted at the highest concentration of 100 mg/L DTPA.

Results with reference substance (positive control):

no data

Reported statistics and error estimates:

no data

Validity criteria fulfilled:

yes

Conclusions:

The NOEC (based on reproduction) was 100 mg/L.

Executive summary:

Adult male and female crimson-spotted rainbowfish were exposed to DTPA in a static-renewal system for a period of 28 days and their reproduction, LSI, GSI, condition factor and EROD activity were assessed. There were no effects of parental DTPA exposure on apical endpoints, such as reproduction or condition factor. The only effect observed during the experiment was a 50% inhibition in activity of the hepatic MFO enzyme ethoxyresorufin O-deethylase in female rainbowfish exposed to 100 mg/L DTPA. This effect is biochemical in nature and is not an appropriate endpoint on which to base risk assessment decisions. Thus, the overall NOEC for the apical endpoints measured in this study (growth, reproduction) is 100 mg/L DTPA.

Description of key information

The 28-day NOEC for reproduction in the crimson-spotted rainbowfish (Melanotaenia fluviatilis) was 100 mg/L DTPA (free acid), which is equivalent to 123 mg/L DTPA-Fe(NH4)2.

The effect observed for DTPA-H5 during a long term fish test as published by van Dam (1999) is read across to DTPA-Fe(NH4)2. This read across is considered justified because the effects observed will be caused by the DTPA-Fe complex. Ammonium, potassium, sodium, hydrogen are only counter ions needed to neutralize the product and these ions will easily dissociate from the DTPA-Fe complex when evaluated in aquatic ecotoxicity tests under ambient conditions.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

123 mg/L

Additional information

One chronic study for fish was available for DTPA (free acid). This study was well documented and met generally accepted scientific principles, and thus, was considered acceptable for assessment. In this study, adult male and female crimson-spotted rainbowfish (Melanotaenia fluviatilis) were exposed to DTPA (free acid) in a static-renewal system for a period of 28 days. Upon contact with water, pentasodium DTPA is expected to dissociate, thus, is it considered essentially equivalent to the free acid form of DTPA in aquatic environments. The endpoints that were measured in this study included reproduction, liver-somatic index, gonadal-somatic index, condition factor and EROD activity. There were no effects of parental DTPA (free acid) exposure on apical endpoints, such as reproduction or condition factor, at the highest test concentration of 100 mg/L DTPA (free acid), which, following stoichiometric conversion, is equivalent to 123 mg/L DTPA-Fe(NH4)2.