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

Endpoint summary

Description of key information

The LD50 value in rats was in excess of 2000 mg/kg bw. Other metal chelates did not show inhalation or dermal toxicity. Non-physiological routes of exposure (iv and ip) also showed low acute toxicity.

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:

October 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well performed and reported GLP study

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

Species: rat, Wistar strain Crl:WI (Han) (outbred, SPF-Quality). Recognized by international guidelines as the recommended test system (e.g. OECD, EC)
Source: Charles River Deutschland, Sulzfeld, Germany
Number of animals: 6 Females (nulliparous and non-pregnant). Each dose group consisted of 3 animals.
Age and body weight: Young adult animals (approx. 8 weeks old) were selected. Body weight variation did not exceed +/- 20% of the sex mean.
Identification: Ear- and tailmark

Conditions
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.

Accommodation
Group housing of 3 animals per cage in labeled Makrolon cages (MIV type; height 18 cm.) containing sterilized sawdust as bedding material (Litalabo, S.P.P.S., Argenteuil, France) and paper as cage-enrichment (Enviro-dri, Wm. Lillico & Son (Wonham Mill Ltd), Surrey, United Kingdom).
Acclimatization period was at least 5 days before start of treatment under laboratory conditions.

Diet
Free access to pelleted rodent diet (SM R/M-Z from SSNIFF® Spezialdiäten GmbH, Soest, Germany).

Water
Free access to tap water.

Diet, water, bedding and cage enrichment evaluation for contaminants and/or nutrients was performed according to facility standard procedures.

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

Method: oral gavage, using plastic feeding tubes.
Fasting: 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.
Frequency: Single dosage on Day 1.
Dose level (volume): 2000 mg/kg (3.11 mL/kg) body weight.
Dose volume calculated as (dose level (g/kg) / density (g/mL)) x 2.08 (A correction was made for purity of the test substance (correction factor 2.08)).

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

6

Control animals:

no

Details on study design:

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. The symptoms were graded according to fixed scales and the time of onset, degree and duration were recorded:
Maximum grade 4: grading slight (1) to very severe (4)
Maximum grade 3: grading slight (1) to severe (3)
Maximum grade 1: presence is scored (1).
Necropsy: 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.

Statistics:

Not needed, limit test

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

act. ingr.

Mortality:

No mortality occurred.

Clinical signs:

other: No clinical signs were noted.

Gross pathology:

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

Other findings:

None

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The oral LD50 value was in excess of 2000 mg/kg bw.

Executive summary:

The study was carried out based on the guidelines described in: OECD No.423 (2001) "Acute Oral Toxicity, Acute Toxic Class Method"; Commission Regulation (EC) No 440/2008, B1 tris: "Acute Oral Toxicity, Acute Toxic Class Method"; EPA, OPPTS 870.1100 (2002), "Acute Oral Toxicity"; JMAFF guidelines (2011) including the most recent partial revisions.

EDTA-MnK2 was administered by oral gavage to two subsequent groups of three female Wistar rats at 2000 mg/kg body weight. Animals were subjected to daily observations and weekly determination of body weight. Macroscopic examination was performed after terminal sacrifice (Day 15).

No mortality occurred and no clinical signs were noted. The body weight gain shown by the animals over the study period was considered to be normal. No abnormalities were found at macroscopic post mortem examination of the animals. The oral LD50value of EDTA-MnK2 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-MnK2 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) andRegulation (EC) No 1272/2008 on classification, labelling and packaging of substances and mixtures.

 

 

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Quality of whole database:

The results of this study together with results of studies with other (metal) chelates provide sufficient data for interpretation.

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

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

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:

yes

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:

Several studies are available for various metal chelates (see read across document in section 13); no toxicity observed.

Acute toxicity: via dermal route

Endpoint conclusion

Quality of whole database:

Studies with two other metal chelates were available both showing LD50 values in excess of 2000 mg/kg bw.

Additional information

The oral route for the endpoint acute toxicity is covered. Several acute inhalation studies with other metal chelates are available (see also read across document in section 13). A third route is not required by Regulation 1907/2006. In addition, the absorption via the skin is expected to be very low (EU RAR, 2004). Acute dermal studies with two other metal chelates showed LD50 values in excess of 2000 mg/kg bw.

Justification for selection of acute toxicity – oral endpoint

Study in rats, OECD guideline 423

Justification for classification or non-classification

Based on the very low toxicity of EDTA-MnK2 via the oral route, and low inhalation and dermal toxicity observed for other metal chelates (see read across document in section 13) the expected very low dermal absorption, no classification is needed for acute toxicity.