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

Endpoint summary

Description of key information

The acute oral toxicity test did not show mortality at a limit dose of 2000 mg/kg bw and the 4-h inhalation toxicity study with the read across substance EDTA-MnNa2 did not show mortality at the limit concentration of 5000 mg/m3. 

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

30 September - 21 October 2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study has been performed according to OECD and/or EC guidelines and according to GLP principles.

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.1 tris (Acute Oral Toxicity - Acute Toxic Class Method)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1100 (Acute Oral Toxicity)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Japanese Ministry of Agriculture, Forestry and Fisheries (JMAFF), 12 Nohsan, Notification No 8147, April 2011, including the most recent partial revisions.

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

no

Species:

rat

Strain:

other: Wistar (Han)

Sex:

female

Details on test animals or test system and environmental conditions:

- Source: Charles River Deutschland, Sulzfeld, Germany.
- Age at study initiation: Young adult animals (approx. 8-10 weeks old)
- Weight at study initiation: Body weight variation was within +/- 20% of the sex mean.
- Fasting period before study: Animals were deprived of food overnight prior to dosing and until 3-4 hours after administration of the test substance. Water was available ad libitum.
- Housing: Group housing of 3 animals per cage in labeled Macrolon cages
- Diet: Free access to pelleted rodent diet (SM R/M-Z from SSNIFF® Spezialdiäten GmbH, Soest, Germany).
- Water: Free access to tap water.
- Acclimation period: At least 5 days

Environmental controls for the animal room were set to maintain 18 to 24°C, a relative humidity of 40 to 70%, approximately 15 room air changes/hour, and a 12-hour light/12-hour dark cycle. Any variations to these conditions were maintained in the raw data and had no effect on the outcome of the study.

IN-LIFE DATES: From: 30 September - 21 October 2014

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

GAVAGE METHOD: plastic feeding tubes.
Frequency: single dosage, on Day 1.

MAXIMUM DOSE VOLUME APPLIED: 2000 mg/kg (4.364 mL/kg) body weight.

Doses:

2000 mg/kg (4.364 mL/kg) body weight.

No. of animals per sex per dose:

6 (2 groups of three females in a stepwise manner)

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing:
Mortality/Viability: Twice daily.
Body weights: Days 1 (pre-administration), 8 and 15.
Clinical signs: At periodic intervals on the day of dosing (Day 1) and once daily thereafter, until Day 15.
- Necropsy of survivors performed: At the end of the observation period, all animals were sacrificed by oxygen/carbon dioxide procedure and subjected to necropsy. Descriptions of all internal macroscopic abnormalities were recorded.
- Other examinations performed: none.

Statistics:

No statistical analysis was performed (the method used is not intended to allow the calculation of a precise LD50 value).

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality occurred.

Clinical signs:

other: Hunched posture and piloerection were noted for all animals between Days 1 and 5.

Gross pathology:

No abnormalities were found at macroscopic post mortem examination of the animals.

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The oral LD50 value of EDTA-Mn(NH4)2 in Wistar rats was established to exceed 2000 mg/kg body weight.

Executive summary:

The oral LD50 value of EDTA-Mn(NH4)2 in Wistar rats was established to exceed 2000 mg/kg body weight. According to the OECD 423 test guideline, the LD50 cut-off value was considered to exceed 5000 mg/kg body weight. Based on these results, EDTA-Mn(NH4)2 does not have to be classified and has no obligatory labelling requirement for acute oral toxicity according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) of the United Nations (2011) (including all amendments) and Regulation (EC) No 1272/2008 on classification, labelling and packaging of substances and mixtures (including all amendments).

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Quality of whole database:

Study result in line with several other chelates (see also read across document in section 13)

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

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

Adequacy of study:

key study

Study period:

April-May 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well conducted study according to GLP

Qualifier:

according to guideline

Guideline:

OECD Guideline 436 (Acute Inhalation Toxicity: Acute Toxic Class Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland, Sulzfeld, Germany
- Age at study initiation: 8 weeks
- Weight at study initiation: 269 g (males), 165 g (females)
- Fasting period before study: not applicable
- Housing: groups of 3, in macrolon cages, with bedding of wood shavings and strips of paper
- Diet (e.g. ad libitum): ad lib, except during exposure
- Water (e.g. ad libitum): ad lib, except during exposure
- Acclimation period: 15 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24
- Humidity (%): 45-65 with short excursions to higher levels during cleaning activities
- Air changes (per hr): ca. 10
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 22 April To: 6 May 2010

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose/head only

Vehicle:

other: water

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: nose only inhalation chamber / modification of ADG Developments Ltd.
- Exposure chamber volume: ca. 50 L
- Method of holding animals in test chamber: in polycarbonate restraining tubes
- Source and rate of air: dry compressed air
- Method of conditioning air: test substance was diluted in water; as such compressed air became humidified
- System of generating particulates/aerosols: atomizing a solution of 650 g EDTA-MnNa2 per L water
- Method of particle size determination: 1- stage cascade impactor
- Treatment of exhaust air: filtered
- Temperature, humidity, pressure in air chamber: 23.4 ± 0.2 (23.1-23.6) degrees C; 86 ± 1% (84.9-86.6%); slightly positive pressure in central exposure cylinder; slightly negative pressure in surrounding hood

TEST ATMOSPHERE
- Brief description of analytical method used: gravimetric analysis
- Samples taken from breathing zone: yes

VEHICLE
- Composition of vehicle (if applicable): water
- Concentration of test material in vehicle (if applicable): 650 g/L
- Justification of choice of vehicle: EDTA-MnNa2 is soluble in water; by atomizing a solution in water and evaporation of the water, respirable particles will be generated
- Lot/batch no. (if required): not applicable
- Purity: not applicable

TEST ATMOSPHERE (if not tabulated)
- Particle size distribution: measured once before exposure and twice during exposure
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.):
measurement 1: MMAD = 3.3 µm, GSD = 2.8
measurement 2: MMAD = 3.2 µm, GSD = 2.5
measurement 3: MMAD = 3.3 µm, GSD = 2.4

CLASS METHOD (if applicable)
- Rationale for the selection of the starting concentration: no acute toxicity expected; therefore starting concentration for aerosol used, viz. 5 mg/L.

Analytical verification of test atmosphere concentrations:

no

Remarks:

not needed in case of gravimetry

Duration of exposure:

4 h

Concentrations:

5.16 mg/L

No. of animals per sex per dose:

3

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: days 0 (prior to exposure), days 1, 3, 7 and 14
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight

Statistics:

Not needes; single exposure only

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 5.16 mg/L air

Based on:

test mat.

Exp. duration:

4 h

Mortality:

None

Clinical signs:

other: None during exposure. Shortly after exposure, slight sniffing was heard in one male and 2 females. A slightly soiled fur of the head was observed in all 3 females. No other abnormalities were seen.

Body weight:

On days 1 and 3, body weighth gain had slowed down. The overall body weight gain in 14 days was as expected for animals of the strain and age.

Gross pathology:

Petechiae were seen on both lobes of the thymus in one male. A petechia aws seen on one lung lobe of one female. These minor abnormalities were not considered to be related to the exposure.

Other findings:

None

Interpretation of results:

study cannot be used for classification

Remarks:

Migrated information

Conclusions:

Because the 4-h LC50 was > 5.16 mg/L and signs observed during and after exposure were very limited, EDTA-MnNa2 is not toxic after inhalation and classification is not needed.

Executive summary:

The aim of the present study was to investigate the acute inhalation toxicity of EDTAMnNa2 in rats. Therefore, three male and three female animals were exposed to a target concentration of 5 g/m3 during a single period of four hours. Animals were kept for an observation period of 14 days before sacrifice. To characterize the toxicity, the animals were observed during exposure, shortly after exposure and daily thereafter, body weight was measured before exposure and 1, 3, 7 and 14 days after exposure and the animals were examined for gross pathological changes at necropsy. The actual concentration of the test compound during exposure was 5.16 g/m3, based on gravimetric analysis of the test atmosphere. Measured mass median aerodynamic diameters were 3.2 and 3.3 µm and the distribution of particle sizes had a geometric standard deviation (gsd) of 2.5 and 2.4, respectively. No abnormalities were seen during exposure. Shortly after exposure, however, sniffing was heard in one male and two female animals and a soiled fur of the head was noticed in all three female animals. The next day, these or other clinical abnormalities were no longer seen. Body weight gain was as expected for animals of this age and strain on days 7 and 14, but was decreased on days 1 and 3. The minor macroscopic abnormalities found at necropsy (petechiae on the lobes of the thymus in one male animal and one petechia on one lung lobe in one female animal) were not considered to be related to the exposure. Mortality did not occur during the 14-day observation period after a 4 -hour exposure by inhalation to a concentration of 5.16 g/m3 of EDTA-MnNa2. It is therefore concluded that the 4-hour LC50 is above 5.16 g/m3 for male and female rats. According to the OECD Guideline for Testing of Chemicals 436 EDTA-MnNa2 should be classified as “unclassified”.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Quality of whole database:

Studies with other metal chelates do not show acute inhalation toxicity (see also read across document in section 13)

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Quality of whole database:

Studies with other metal chelates do not show acute dermal toxicity (see also read across document in section 13)

Additional information

Because there was no mortality, the oral LD50 of EDTA-Mn(NH4)2 is in excess of 2000 mg/kg bw; the 4 -h LC50 value of the read across substance EDTA-MnNa2 is higher than 5.16 mg/L.

In an acute study in Swiss mice both MnSO4.H2O and a 1:1 mixture of MnSO4.H2O and EDTA-Na2H2/EDTA-Na4 were tested via a single intraperitoneal injection. The LD50 of the read across substance EDTA-MnNa2 turned out to be 2332 mg EDTA-MnNa2 per kg bw. On a molar basis EDTA-MnNa2 was 7.5 times less toxic than the metal salt MnSO4.H2O.

Justification for selection of acute toxicity – oral endpoint
Well performed study according to GLP

Justification for selection of acute toxicity – inhalation endpoint
Well performed study with the read across substance EDTA-MnNa2

Justification for classification or non-classification

Because of the absence of mortality at the limit concentration tested in the oral study, and based on the absence of mortality with the read across substances tested in dermal and inhalation studies, no classification is needed.