Nickel(2+) diammonium 2,2',2'',2'''-(ethane-1,2-dinitrilo)tetraacetate

Endpoint summary

Description of key information

As prooved by the studies, the toxicity of edetic acid is much lower than of nickel(2 +) salts. Ammonium cations are known to be non-toxic. Thus the acute orla toxicity of EDTA-Ni(NH4)2 is determined by the nickel moiety.

Regarding the molecular weight of EDTA-Ni(NH4)2 an oral LD50 value >= 300 mg/kg bw could be concluded, which leads to the category 4 classification according to the regulation 1272/2008 (CLP-Regulation).

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Reference 1

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1988

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Peer reviewed publication in Am. J. of Ind. Medicine. Main author is an authority in research of nickel poisoning. Detailed monitoring of workers accidentally exposed to toxic leves of Ni.

Qualifier:

no guideline required

Principles of method if other than guideline:

Concentrations of drinking water containing NiS04 · 6H20 and NiCl2 · 6H20 (1.63 gl!iter), caused by leakage from a Nickel-plating tank, were absorbed by exposed or non-exposed workers.

GLP compliance:

not specified

Test type:

other: Monitoring of workers after accidental exposure to toxic concentrations of Ni in drinking water.

Specific details on test material used for the study:

The test material was drinking water containing NiS04 · 6H20 and NiCl2 · 6H20 (1.63 gl!iter), caused by leakage from a Nickel-plating tank.

Species:

other: human

Sex:

male

Details on test animals or test system and environmental conditions:

Age: 17-36 years

Route of administration:

oral: drinking water

Vehicle:

water

Details on oral exposure:

Workers drank different volumes of contaminated water during a period of approx. 14 h

Doses:

estimated total intake: 0.5 to 2.5 g Ni2+

No. of animals per sex per dose:

Group A: 21 exposed workers, 18 with symptoms, 10 hospitalized; examined from day 1
Group B: 11 exposed workers, 2 with mild symptoms; examined from day 3
Group C: 11 non-exposed workers on the same production line (control)

Control animals:

yes

Details on study design:

- Duration of observation period following contamination: 5 days
- Frequency of observations: on days 1, 2, 3 & 5
- Examinations performed:
all: - urine: Ni-concentration, creatinine, albumin
- serum: Ni-concentration, urea, creatinine, creatinine kinase, lactate dehydrogenase, aspartate aminotransferase, alanine aminotransferase, alkaline phophatase.
hospitalized workerd (n=10): chest X-ray, electrocardiogram, creatinine clearance, urine total protein, blood leukocyte, platelet and reticulocyte counts, blood hemoglobin, pH, pCO2 and pO2, serum glucose, sodium, potassium, chloride, bicarbonate, bilirubin, calcium, cortisol, prothrombin time, partial thromboplastin time, fibrinogen, fibrin split products
- Other examinations (6 wks after exposure): follow-up studies incl. physical examination, urinalysis, blood hemoglobin, reticulocyte counts

Statistics:

Statistical computations (c.g., linear and exponential regression, analysis of var:iance, Student's t-test, Fisher's exact test, and Mann-Whitney U test) were performed according to Saehs [1.984].

Key result

Dose descriptor:

LD0

Effect level:

>= 33 mg/kg bw

Remarks on result:

other: The value was calculated considering the highest value of Ni uptaken (2.5 g) and assuming a human weight of 75 Kg

Clinical signs:

other: The following complaints were voiced by the 20 symptomatic workers: nausea (N=15), abdominal cramps or discomfort (N = 14), giddiness (N = 7), lassitude (N = 6), headache (N = 5), diarrhea (N = 4), vomiting (N = 3), shortness ofbreath (N =2), cough (N= 1)

Other findings:

No abnormalities were found by the routine laboratory tests (urinalysis, blood count) performed during the initial clinical evaluations

All subjects became asymptomatic within 3 days postexposure.

Workers with Ni concentrations in urine > 1.5 mg/l were hospitalized and treated by diuresis, thier T1/2 for Ni-removal from serum was 27 h, while T1/2 of non-hospitalized workers was 60 h.

Hospitalized workers showed significantly elevated levels of blood hemoglobin and reticulocyte counts from day 3 postexposure to day 8 (paired t-test:p<0.01).

Mild hyperbilirubinemia developed on day 3 postexposure in two of the subjects.

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

1. Direct symptoms of Ni poisoning were comparable to earlier findings and lasted up to 48 h after exposure.
2. The retention t1/2 if Ni in serum did not significantly correlate with the initial concentrations of Ni in the serum.
3. Induced diuresis succesfully decreased the retention t1/2 of Ni in blood serum from 60 h to 27 h.
4. Ni poisoning induced mild erythrocytosis and reticulocytosis.

Reference 2

Endpoint:

acute toxicity: oral

Type of information:

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

Adequacy of study:

key study

Study period:

1988

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Peer reviewed publication in Am. J. of Ind. Medicine. Main author is an authority in research of nickel poisoning. Detailed monitoring of workers accidentally exposed to toxic leves of Ni.

Justification for type of information:

The complex EDTA-Ni(NH4)2 consists of the organic moiety EDTA, the central atom Ni2+ and the ammonium ions. As the ammonium ions are known to be non-toxic only the EDTA-Ni complex must be regarded as toxic. For both, free EDTA and Ni2+ compounds well-documented studies are available, which shows their toxicity. For EDTA, LD50 values of > 2,000 mg/kg in rats were reported, that lead to no classification and labelling for acute oral toxicity for EDTA (source: EU SUMMARY RISK ASSESSMENT REPORT prepared in 2004 by BAuA in Germany). In general, the complex with the chelated Ni2+ ion should be less toxic than the free Ni2+ ion. Based on that and that the complex EDTA-Ni has an average stability, a worst-case assessment where the EDTA-Ni(NH4)2 complex dissociate in its components can be done and so a read-across is possible to free EDTA and other Ni2+ compounds.

Reason / purpose for cross-reference:

read-across source

Qualifier:

no guideline required

Principles of method if other than guideline:

Concentrations of drinking water containing NiS04 · 6H20 and NiCl2 · 6H20 (1.63 gl!iter), caused by leakage from a Nickel-plating tank, were absorbed by exposed or non-exposed workers.

GLP compliance:

not specified

Test type:

other: Monitoring of workers after accidental exposure to toxic concentrations of Ni in drinking water.

Specific details on test material used for the study:

The test material was drinking water containing NiS04 · 6H20 and NiCl2 · 6H20 (1.63 gl!iter), caused by leakage from a Nickel-plating tank.

Species:

other: human

Sex:

male

Details on test animals or test system and environmental conditions:

Age: 17-36 years

Route of administration:

oral: drinking water

Vehicle:

water

Details on oral exposure:

Workers drank different volumes of contaminated water during a period of approx. 14 h

Doses:

estimated total intake: 0.5 to 2.5 g Ni2+

No. of animals per sex per dose:

Group A: 21 exposed workers, 18 with symptoms, 10 hospitalized; examined from day 1
Group B: 11 exposed workers, 2 with mild symptoms; examined from day 3
Group C: 11 non-exposed workers on the same production line (control)

Control animals:

yes

Details on study design:

- Duration of observation period following contamination: 5 days
- Frequency of observations: on days 1, 2, 3 & 5
- Examinations performed:
all: - urine: Ni-concentration, creatinine, albumin
- serum: Ni-concentration, urea, creatinine, creatinine kinase, lactate dehydrogenase, aspartate aminotransferase, alanine aminotransferase, alkaline phophatase.
hospitalized workerd (n=10): chest X-ray, electrocardiogram, creatinine clearance, urine total protein, blood leukocyte, platelet and reticulocyte counts, blood hemoglobin, pH, pCO2 and pO2, serum glucose, sodium, potassium, chloride, bicarbonate, bilirubin, calcium, cortisol, prothrombin time, partial thromboplastin time, fibrinogen, fibrin split products
- Other examinations (6 wks after exposure): follow-up studies incl. physical examination, urinalysis, blood hemoglobin, reticulocyte counts

Statistics:

Statistical computations (c.g., linear and exponential regression, analysis of var:iance, Student's t-test, Fisher's exact test, and Mann-Whitney U test) were performed according to Saehs [1.984].

Key result

Dose descriptor:

LD0

Effect level:

>= 33 mg/kg bw

Remarks on result:

other: The value was calculated considering the highest value of Ni uptaken (2.5 g) and assuming a human weight of 75 Kg

Clinical signs:

other: The following complaints were voiced by the 20 symptomatic workers: nausea (N=15), abdominal cramps or discomfort (N = 14), giddiness (N = 7), lassitude (N = 6), headache (N = 5), diarrhea (N = 4), vomiting (N = 3), shortness ofbreath (N =2), cough (N= 1)

Other findings:

No abnormalities were found by the routine laboratory tests (urinalysis, blood count) performed during the initial clinical evaluations

All subjects became asymptomatic within 3 days postexposure.

Workers with Ni concentrations in urine > 1.5 mg/l were hospitalized and treated by diuresis, thier T1/2 for Ni-removal from serum was 27 h, while T1/2 of non-hospitalized workers was 60 h.Hospitalized workers showed significantly elevated levels of blood hemoglobin and reticulocyte counts from day 3 postexposure to day 8 (paired t-test:p<0.01). Mild hyperbilirubinemia developed on day 3 postexposure in two of the subjects.

Regarding the molecular weight of EDTA-Ni(NH4)2 an oral LD0 value of >= 215 mg/kg bw could be calculated. Therefore the LD 50 is for sure > 215 mg/kg bw an we assume that is >= 300 mg/kg bw,which leads to the category 4 classification according to the regulation 1272/2008 (CLP-Regulation).

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

1. Direct symptoms of Ni poisoning were comparable to earlier findings and lasted up to 48 h after exposure.
2. The retention t1/2 if Ni in serum did not significantly correlate with the initial concentrations of Ni in the serum.
3. Induced diuresis succesfully decreased the retention t1/2 of Ni in blood serum from 60 h to 27 h.
4. Ni poisoning induced mild erythrocytosis and reticulocytosis.

Executive summary:

Regarding the molecular weight of EDTA-Ni(NH4)2 an oral LD0 value of >= 215 mg/kg bw could be recalculated by molecular weight correction. No LD50 is reported by the study due to the fact that these are human data. No serious poisoning effects were observed at this dosis. It can be concluded that the LD50 value will be higher than 300 mg/kg bw because otherwise more toxic effects would have been observed at a dosis equivalent to 215 mg/kg bw. Therefore the LD50 is >= 300 mg/kg bw, which leads to the category 4 classification according to the regulation 1272/2008 (CLP-Regulation).

Reference 3

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 425 (Acute Oral Toxicity: Up-and-Down Procedure)

GLP compliance:

yes

Test type:

up-and-down procedure

Specific details on test material used for the study:

In the study, different Nickel compounds were tested. We consiedered the test item Ni sulphate hexahydrate (CAS 10101-97-0) (purity >= 99%), since the LD50 was the lowest found in the test (with exclusion of Ni fluoride, that was not considered because the toxicity is known to derive also from the ion fluoride). Test item was provided by members of the Nickel REACH Consortia.

Species:

rat

Strain:

Sprague-Dawley

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Received from Ace Animals, Inc., Boyertown, PA on July 22 and August 5, 2008.
- Age at study initiation: 9-12 weeks
- Weight at study initiation: 171-232 grams
- Fasting period before study: not reported
- Housing: singly housed in suspended stainless steel caging with mesh floors
- Diet (e.g. ad libitum): ad libitum (Purina Rodent Chow #5012)
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 10-28 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18-24°C
- Humidity (%): 15-70%,
- Air changes (per hr): not reported
- Photoperiod (hrs dark / hrs light): 12-hour light/dark cycle

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

VEHICLE: 60% w/w mixture in distilled water
MAXIMUM DOSE VOLUME APPLIED: 2000 mg/kg

Doses:

159, 200, 250, 2000 mg/kg
Individual doses were calculated based on the initial body weights.

No. of animals per sex per dose:

2 per dose

Details on study design:

The main test consists of single ordered dose progression, where one animal is dosed at a higher or lower dose than the previous until one of the stopping criteria have been met (OECD, 2006). When testing at the Iimit dose, the study is stopped after three consecutive animals survive at the upper bound Iimit. Following administration, each animal was returned to its designated cage. Feed was replaced approximately 3-4 hours after dosing. Observed up to 14 days.
- Frequency of observations and weighing: days 0, 7, and 14
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs and body weight measured

Statistics:

The Acute Oral Toxicity (Guideline 425) Statistical Program (Weststat, version 1.0, May 2001) was used for all data analyses including: dose progression selections, stopping criteria determinations and/or LD50 and confidence limit calculations.

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

>= 80.84 mg/kg bw

Remarks on result:

other: The LD50 was re-calculated based on the atomic weight of Ni

Mortality:

159 mg/kg: 0/2
200 mg/kg: 1/2
250 mg/kg: 0/1
2000 mg/kg: 1/1

Clinical signs:

other: 159 mg/kg: There were no signs of gross toxicity, adverse pharmacologic effects, or abnormal behavior.One rat exhibited pi!oerection on day I. 200 mg/kg: Rats exhibited hypoactivity and/or piloerection and red intestines. 250 mg/kg: There were no signs o

Gross pathology:

200 mg/kg: Rats exhibited red intestines.
2000 mg/kg: All animals exhibited abnormal posture and red intestines.

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

The acute oral LD50 of Ni sulphate hexahydrate (CAS 10101-97-0) in female rats was estimated to be 362 mg/kg-bw. A NOAEL of 159 mg/kg bw was observed. A LD >= 80.84 was re-calculated for Nickel, based on its atomic weight.

Reference 4

Endpoint:

acute toxicity: oral

Type of information:

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

Adequacy of study:

key study

Study period:

2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

The complex EDTA-Ni(NH4)2 consists of the organic moiety EDTA, the central atom Ni2+ and the ammonium ions. As the ammonium ions are known to be non-toxic only the EDTA-Ni complex must be regarded as toxic. For both, free EDTA and Ni2+ compounds well-documented studies are available, which shows their toxicity. For EDTA, LD50 values of > 2,000 mg/kg in rats were reported, that lead to no classification and labelling for acute oral toxicity for EDTA (source: EU SUMMARY RISK ASSESSMENT REPORT prepared in 2004 by BAuA in Germany). In general, the complex with the chelated Ni2+ ion should be less toxic than the free Ni2+ ion. Based on that and that the complex EDTA-Ni has an average stability, a worst-case assessment where the EDTA-Ni(NH4)2 complex dissociate in its components can be done and so a read-across is possible to free EDTA and other Ni2+ compounds.

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 425 (Acute Oral Toxicity: Up-and-Down Procedure)

GLP compliance:

yes

Test type:

up-and-down procedure

Specific details on test material used for the study:

In the study, different Nickel compounds were tested. We consiedered the test item Ni sulphate hexahydrate (CAS 10101-97-0) (purity >= 99%), since the LD50 was the lowest found in the test (with exclusion of Ni fluoride, that was not considered because the toxicity is known to derive also from the ion fluoride). Test item was provided by members of the Nickel REACH Consortia.

Species:

rat

Strain:

Sprague-Dawley

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Received from Ace Animals, Inc., Boyertown, PA on July 22 and August 5, 2008.
- Age at study initiation: 9-12 weeks
- Weight at study initiation: 171-232 grams
- Fasting period before study: not reported
- Housing: singly housed in suspended stainless steel caging with mesh floors
- Diet (e.g. ad libitum): ad libitum (Purina Rodent Chow #5012)
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 10-28 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18-24°C
- Humidity (%): 15-70%,
- Air changes (per hr): not reported
- Photoperiod (hrs dark / hrs light): 12-hour light/dark cycle

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

VEHICLE: 60% w/w mixture in distilled water
MAXIMUM DOSE VOLUME APPLIED: 2000 mg/kg

Doses:

159, 200, 250, 2000 mg/kg
Individual doses were calculated based on the initial body weights.

No. of animals per sex per dose:

2 per dose

Details on study design:

The main test consists of single ordered dose progression, where one animal is dosed at a higher or lower dose than the previous until one of the stopping criteria have been met (OECD, 2006). When testing at the Iimit dose, the study is stopped after three consecutive animals survive at the upper bound Iimit. Following administration, each animal was returned to its designated cage. Feed was replaced approximately 3-4 hours after dosing. Observed up to 14 days.
- Frequency of observations and weighing: days 0, 7, and 14
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs and body weight measured

Statistics:

The Acute Oral Toxicity (Guideline 425) Statistical Program (Weststat, version 1.0, May 2001) was used for all data analyses including: dose progression selections, stopping criteria determinations and/or LD50 and confidence limit calculations.

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

>= 80.84 mg/kg bw

Remarks on result:

other: The LD50 was re-calculated based on the atomic weight of Ni

Mortality:

159 mg/kg: 0/2
200 mg/kg: 1/2
250 mg/kg: 0/1
2000 mg/kg: 1/1

Clinical signs:

other: 159 mg/kg: There were no signs of gross toxicity, adverse pharmacologic effects, or abnormal behavior.One rat exhibited pi!oerection on day I. 200 mg/kg: Rats exhibited hypoactivity and/or piloerection and red intestines. 250 mg/kg: There were no signs o

Gross pathology:

200 mg/kg: Rats exhibited red intestines.
2000 mg/kg: All animals exhibited abnormal posture and red intestines.

Regarding the molecular weight of EDTA-Ni(NH4)2 an oral LD50 value of 527 mg/kg bw could be calculated.

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

The acute oral LD50 of Ni sulphate hexahydrate (CAS 10101-97-0) in female rats was estimated to be 362 mg/kg-bw. A NOAEL of 159 mg/kg bw was observed. A LD >= 80.84 was re-calculated for Nickel, based on its atomic weight.
Regarding the molecular weight of EDTA-Ni(NH4)2 an oral LD50 value of 527 mg/kg bw could be calculated, which leads to the category 4 classification according to the regulation 1272/2008 (CLP-Regulation).

Reference 5

Endpoint:

acute toxicity: oral

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: Comparable to OECD 401 guideline study with acceptable restrictions [Body weight was only determined at the beginning of the study (OECD: weekly); Observation period: 7 days (OECD:14 days)]

Justification for type of information:

The complex EDTA-Ni(NH4)2 consists of the organic moiety EDTA, the central atom Ni2+ and the ammonium ions. As the ammonium ions are known to be non-toxic only the EDTA-Ni complex must be regarded as toxic. For both, free EDTA and Ni2+ compounds well-documented studies are available, which shows their toxicity. In general, the complex with the chelated Ni2+ ion should be less toxic than the free Ni2+ ion. Based on that and that the complex EDTA-Ni has an average stability, a worst-case assessment where the EDTA-Ni(NH4)2 complex dissociate in its components can be done and so a read-across is possible to free EDTA and other Ni2+ compounds.

Reason / purpose for cross-reference:

read-across source

Principles of method if other than guideline:

BASF-TEST: In principle, the methods described in the OECD Guideline 401 were used. Young adult laboratory rats were purchased from breeder. Usually the source and strain of animals were not documented. Several groups of 5 rats per sex and dose were treated simultaneously by gavage with preparations of the test substance in suitable vehicle. The concentrations of these preparations were used to achieve comparable volumes per kg body weight. Group-wise documentation of clinical signs was performed over the 7 day study period. Body weight was determined before the start of the study only, as it was needed for determination of dose

GLP compliance:

no

Test type:

standard acute method

Species:

rat

Strain:

not specified

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Mean body weight at study initiation:
259 g males/ 211 g females

Route of administration:

oral: gavage

Vehicle:

CMC (carboxymethyl cellulose)

Details on oral exposure:

DOSAGE PREPARATION:
- Stock solutions prepared: 30 %
- Dose volume applied: 2500 mg/kg bw dose group:
8.33 mL/kg bw
3200 mg/kg bw dose group: 10.66 mL/kg bw
4000 mg/kg bw dose group: 13.33 mL/kg bw
5000 mg/kg bw dose group: 16.66 mL/kg bw
6400 mg/kg bw dose group: 21.4 mL/kg bw

Doses:

2500; 3200; 4000; 5000; 6400 mg/kg bw

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 7 days;
- The animals were observed for mortality and clinical signs of toxicity;
- Frequency of observations: Several times on the application day, thereafter once each working day;
- Body weights were only recorded at the beginning of the study;
- Necropsy of survivors and animals which died performed: yes

Sex:

male/female

Dose descriptor:

LD50

Effect level:

2 800 mg/kg bw

Mortality:

- One female died in the 2500 mg/kg bw dose group; 9/10 animals died in the 3200 mg/kg bw dose group and all animals of the higher dose groups (see "Any other information on results incl. tables").

Clinical signs:

other: - 2500, 3200 and 4000 mg/kg bw: directly after application: accelerated respiration, squatting posture, twitching, ataxia, red eyes, some animals showed light secretion, reluctance to move; the next day: squatting posture, contaminated fur, intermittened

Gross pathology:

Animals which died:
- heart: acute dilatation, venous hyperemia
- liver: congestion
- gut: diarrhea like content
- stomach: dilatation
- kidneys: degeneration
Animals which were sacrificed:
- nothing abnormal detected

Table 1: Mortalities of rats after oral application

		2500 mg/kg bw	3200 mg/kg bw	4000 mg/kg bw	5000 mg/kg bw	6400 mg/kg bw
1 h	male	0/5	0/5	0/5	0/5	0/5
	female	0/5	0/5	0/5	0/5	0/5
24 h	male	0/5	3/5	5/5	5/5	5/5
	female	1/5	5/5	5/5	5/5	5/5
48 h	male	0/5	3/5	5/5	5/5	5/5
	female	1/5	5/5	5/5	5/5	5/5
7 d	male	0/5	4/5	5/5	5/5	5/5
	female	1/5	5/5	5/5	5/5	5/5

Interpretation of results:

GHS criteria not met

Conclusions:

The LD50 of the test substance EDTA-Na2 is 2800 mg/kg bw which leads to no classification as acute toxicity oral in accordance with regulation (EC) No 1272/2008 (CLP-regulation).

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

300 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

The complex EDTA-Ni(NH4)2 consists of the organic moiety EDTA, the central atom Ni2+ and the ammonium ions. As the ammonium ions are known to be non-toxic only the EDTA-Ni complex must be regarded as toxic. For both, free EDTA and Ni2+ compounds well-documented studies are available, which shows their toxicity. In general, the complex with the chelated Ni2+ ion should be less toxic than the free Ni2+ ion. Based on that and that the complex EDTA-Ni has an average stability (stability constant K>=10^18; Environ. Sci. Technol. 2000, 34, 1715-1720), a worst-case assessment where the EDTA-Ni(NH4)2 complex dissociate in its components can be done and so a read-across is possible to free EDTA and other Ni2+ compounds.

The LD50 of the test substance EDTA-Na2 is 2800 mg/kg bw which leads to no classification as acute toxicity oral in accordance with regulation (EC) No 1272/2008 (CLP-regulation). Therefore, special attention must be paid to the central atom nickel of the EDTA complex.

For different nickel(II) compounds oral LD50 values were determined in well documented studies which meets generally accepted scientific principles and are acceptable for the assessment. Regarding the molecular weight of EDTA-Ni(NH4)2 an oral LD50 value >= 300 mg/kg bw could be concluded, which leads to the category 4 classification according to the regulation 1272/2008 (CLP-Regulation).