Manganese oxalate

Endpoint summary

Description of key information

Acute oral toxicity:
The test item Manganese Oxalate, dihydrate did not cause any mortality or necropsy findings after single oral gavage administration to female rats at 2000 mg/kg bw in a GLP compliant guideline study. Thus the LD50 of the submission substance (Manganese Oxalate, anhydrous form) was expected to be greater than 2000 mg/kg body weight.
Acute dermal toxicity:
The test item Manganese Oxalate, dihydrate did not cause any mortality or necropsy findings after single dermal administration to male and female rats at 2504 mg/kg bw in a GLP compliant guideline study. Thus the LD50 of the submission substance (Manganese Oxalate, anhydrous form) was calculated to be greater than 2000 mg/kg body weight.

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:

05 August 2010 to 01 September 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well performed GLP and OECD guideline study

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

GLP compliance:

yes

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:

Animals: Rat, RccHan: WIST(SPF)

Breeder: Harlan Laboratories B.V.; Kreuzelweg 53; 5961 NM Horst / The Netherlands

Number of Animals per Group: 3 females
Total Number of Animals: 6 females

Age (when treated): 10 weeks
Body Weight Range (when treated): 163.6 g - 195.7 g

Identification: Unique cage number and corresponding color-coded spots on the tail. The animals were marked at acclimatization start.
Randomization: Selected by hand at time of delivery. No computer generated randomization program.

Acclimatization: 5 (Group 1) or 8 (Group 2) days under laboratory conditions, after health examination. Only animals without any visible signs of illness were used for the study.

Conditions: Standard Laboratory Conditions. Air-conditioned with 10-15 air changes per hour, and continuously monitored environment with a room temperature of 22 ± 3 °C and a relative humidity between 30-70%, automatically controlled light cycle of 12 hours light and 12 hours dark and music played during the daytime light period.

Accommodation: In groups of three in Makrolon type-4 cages with wire mesh tops and standard softwood bedding (‘Lignocel’ J. Rettenmaier&Söhne GmbH&CoKG, 73494 Rosenberg / Germany, imported by Provimi Kliba AG, 4303 Kaiseraugst / Switzerland). Paper enrichment, Reference no. 207057, batch no. -67, (Enviro-dri from Lillico, Biotechnology, Surrey / UK) was included.

Diet: Pelleted standard Teklad Rat-Mouse Diet 2914C, irradiated, batch no. 30/10 (Provimi Kliba AG, 4303 Kaiseraugst / Switzerland) ad libitum (except for the overnight fasting period prior to intubation and approximately 3-4 hours post dose). Results of analyses for contaminants are archived at Harlan Laboratories Ltd.

Water: Community tap water from Füllinsdorf ad libitum. Results of bacteriological, chemical and contaminant analyses are archived at Harlan Laboratories Ltd.

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

Preparation of Dose Formulations:

Dose levels are in terms of the test item as supplied by the Sponsor. The dose formulations were prepared shortly before each dosing occasion using a magnetic stirrer and an Ultra-Turrax as homogenizers. The test item was weighed into a tared glass beaker on a suitable precision balance and the vehicle added (weight:volume). Homogeneity of the test item in the vehicle was maintained during administration using a magnetic stirrer.


Test Item Administration:

The animals received a single dose of the test item by oral gavage administration at 2000 mg/kg body weight after being fasted for approximately 17 to 19 hours (access to water was permitted). Food was provided again approximately 3 hours after dosing. Dosing started in three female animals at a dosage level of 2000 mg/kg. The test procedure followed the scheme as described in the guidelines: Test Procedure with a Starting Dose of 2000 mg/kg body weight, Annex 2d, OECD Guideline 423, adopted 17th December 2001. The dosing volume was 10 mL/kg body weight. Rationale: Oral administration was considered to be an appropriate application method as it is a possible route of human exposure during manufacture, handling and use of the test item.

Doses:

2000 mg/kg body weight (equivalent to 1597 mg of the anhydrous form of the substance/kg bodyweight)

No. of animals per sex per dose:

3 animals per dose group, 2 dose groups

Control animals:

no

Details on study design:

Observations:

Viability / Mortality: Daily during acclimatization. Once before treatment and within the first 30 minutes and at approximately 1, 2, 3 and 5 hours after treatment on test day 1 (in common with the clinical signs). Twice daily during days 2 – 15.
Clinical Signs: Daily during acclimatization and treatment. Additionally, within the first 30 minutes and at approximately 1, 2, 3 and 5 hours after administration on test day 1.
Body Weights: On test days 1 (prior to administration), 8 and 15.


Pathology / Necropsy
All animals were killed at the end of the observation period by carbon dioxide asphyxiation and discarded after macroscopic examinations were performed. An external examination and opening of the abdominal and thoracic cavities for examinations of major organs was performed. The appearance of any macroscopic abnormalities was recorded. No organs or tissues were retained.

Statistics:

None

Sex:

female

Dose descriptor:

LD50

Effect level:

> 1 597 mg/kg bw

Based on:

other: the anhydrous form of the substance ( = submission substance)

Remarks on result:

other: equivalent to >2000 mg of the test item (= the dihydrous form) per kg body weight

Mortality:

No intercurrent deaths occurred during the course of the study.

Clinical signs:

No clinical signs were observed throughout the entire observation period.

Body weight:

The body weight of the animals was within the range commonly recorded for this strain and age.

Gross pathology:

No macroscopic findings were observed at necropsy.

Other findings:

None

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The median lethal dose of Manganese oxalate, dihydrate after single oral administration to female rats, observed over a period of 14 days, is:
LD50 (female rat): greater than 2000 mg/kg body weight

Executive summary:

Two groups, each consisting of three female RccHan:WIST (SPF) rats, were treated with Manganese oxalate, dihydrate by single oral gavage administration at a dosage of 2000 mg/kg body weight. The test item was formulated in purified water at a concentration of 0.2 g/mL and administered at a dosing volume of 10 mL/kg.

 

The animals were examined daily during the acclimatization period and mortality, viability and clinical signs were recorded. All animals were examined for clinical signs before treatment, within the first 30 minutes and approximately 1, 2, 3 and 5 hours after treatment on day 1 and once daily during test days 2-15. Mortality/viability was recorded before treatment, within the first 30 minutes and approximately 1, 2, 3 and 5 hours after administration on test day 1 (with the clinical signs) and twice daily during days 2-15. Body weights were recorded on day 1 (prior to administration) and on days 8 and 15. All animals were necropsied and examined macroscopically.

 

No intercurrent deaths occurred during the course of the study.

 

No clinical signs were observed during the course of the study.

 

The body weight of the animals was within the range commonly recorded for this strain and age.

 

No macroscopic findings were observed at necropsy.

 

The median lethal dose of Manganese oxalate, dihydrate after single oral administration to female rats, observed over a period of 14 days, is:

 

LD₅₀(female rat): greater than 2000 mg/kg body weight

Remark:

In this study dosing was not adjusted to the submission substance (Manganese Oxalate), which is the anhydrous form of the test item (Manganes Oxalate, dihydrate). As a consequence the LD50 of the submission substance is calculated to be greater than 1597 mg/kg bw..

However, since no lethality and no relevant toxicity occured in this study, the LD50 of the submission substance (Manganes oxalate) is considered to be greater than 2000 mg/kg body weight.

 

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

discriminating dose

Value:

2 000 mg/kg bw

Quality of whole database:

Reliable without restrictions - well performed GLP and OECD guideline study.
Exception: The test item Manganese Oxalate, dihydrate was tested at the limit dose of 2000 mg/kg bw.. This value is equivalent to 1597 mg/kg bw. of the submission substance (Manganese Oxalate, anhydrous form) resulting in an LD50 value of >1597 mg of the submission substance per kg bw. However this underdosing in absolute terms of the submission substance seems to be negligible because the fact that systemic effects were observed neither in this study nor in any other endpoint studies, suggests that lethality will not occure at dose levels up to 2000 mg/kg bw of the submission substance. Consequently an LD50 of >2000 mg/kg bw. is expected for the submission substance. Therfore the value used for CSA is decided to be 2000 mg/kg bw.

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Between 02 May 2012 and 23 May 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well performed GLP and OECD guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.3 (Acute Toxicity (Dermal))

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

Five male and five female Wistar (RccHan:WIST) strain rats were supplied by Harlan Laboratories UK Ltd., Oxon, UK. On receipt the animals were randomly allocated to cages. The females were nulliparous and non pregnant. After an acclimatisation period of at least five days the animals were selected at random and given a number unique within the study by indelible ink-marking on the tail and a number written on a cage card. At the start of the study the animals weighed at least 200 g, and were eight to twelve weeks of age. The weight variation did not exceed ±20% of the mean weight for each sex.

The animals were housed in suspended solid floor polypropylene cages furnished with woodflakes. The animals were housed individually during the 24 Hour exposure period and in groups of up to four, by sex, for the remainder of the study. Free access to mains drinking water and food (2014C Teklad Global Rodent diet supplied by Harlan Laboratories UK Ltd., Oxon, UK) was allowed throughout the study. The diet, drinking water and bedding were routinely analysed and were considered not to contain any contaminants that could reasonably be expected to affect the purpose or integrity of the study.

The temperature and relative humidity were set to achieve limits of 19 to 25°C and 30 to 70% respectively. Any occasional deviations from these targets were considered not to have affected the purpose or integrity of the study. The rate of air exchange was at least fifteen changes per hour and the lighting was controlled by a time switch to give twelve hours continuous light (06:00 to 18:00) and twelve hours darkness.

The animals were provided with environmental enrichment items which were considered not to contain any contaminant of a level that might have affected the purpose or integrity of the study.

Type of coverage:

semiocclusive

Vehicle:

arachis oil

Details on dermal exposure:

The appropriate amount of test item, moistened with arachis oil BP, was applied as evenly as possible to an area of shorn skin (approximately 10% of the total body surface area).

Duration of exposure:

24 hours

Doses:

2504 mg/kg bodyweight (equivalent to 2000 mg of the anhydrous form of the substance/kg bodyweight)

No. of animals per sex per dose:

5 Male
5 Female

Control animals:

not required

Details on study design:

On the day before treatment the back and flanks of each animal were clipped free of hair.
In the absence of data suggesting the test item was toxic, one male and one female rat were initially treated with the test item at a dose level of 2504 mg/kg (equivalent to 2000 mg of the anhydrous form of the substance/kg bodyweight).
The appropriate amount of test item, moistened with arachis oil BP, was applied as evenly as possible to an area of shorn skin (approximately 10% of the total body surface area). A piece of surgical gauze was placed over the treatment area and semi occluded with a piece of self adhesive bandage. The animals were caged individually for the 24 hour exposure period. Shortly after dosing the dressings were examined to ensure that they were securely in place.
After the 24-hour contact period the bandage was carefully removed and the treated skin and surrounding hair wiped with cotton wool moistened with arachis oil BP to remove any residual test item.
As no mortalities were noted a further group of animals (four males and four females) was similarly treated with the test item at a dose level of 2504 mg/kg bodyweight (equivalent to 2000 mg of the anhydrous form of the substance/kg bodyweight) to give a total of five males and five females. After the 24 hour contact period the bandages were carefully removed and the treated skin and surrounding hair wiped with cotton wool moistened with arachis oil BP to remove any residual test item. These animals were returned to group housing for the remainder of the test period.
The animals were observed for deaths or overt signs of toxicity ½, 1, 2 and 4 hours after dosing and subsequently once daily for fourteen days.
After removal of the dressings and subsequently once daily for fourteen days, the test sites were examined for evidence of primary irritation and scored according to the following scale from Draize J H (1977) "Dermal and Eye Toxicity Tests" In: Principles and Procedures for Evaluating the Toxicity of Household Substances, National Academy of Sciences, Washington DC p.31:

EVALUATION OF SKIN REACTIONS
Erythema and Eschar Formation Value

No erythema 0
Very slight erythema (barely perceptible) 1
Well-defined erythema 2
Moderate to severe erythema 3
Severe erythema (beef redness) to slight eschar formation (injuries in depth) 4

Oedema Formation

No oedema 0
Very slight oedema (barely perceptible) 1
Slight oedema (edges of area well-defined by definite raising) 2
Moderate oedema (raised approximately 1 millimetre) 3
Severe oedema (raised more than 1 millimetre and extending beyond the area of exposure) 4

Any other skin reactions, if present were also recorded.
Individual bodyweights were recorded prior to application of the test item on Day 0 and on Days 7 and 14.
At the end of the study the animals were killed by cervical dislocation. All animals were subjected to gross necropsy. This consisted of an external examination and opening of the abdominal and thoracic cavities. The appearance of any macroscopic abnormalities was recorded. No tissues were retained.

Statistics:

No statistical analysis was performed.

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

other: the anhydrous form of the substance/kg bodyweight

Remarks on result:

other: equivalent to >2504 mg of the test item (= the dihydrous form) per kg body weight

Mortality:

There were no deaths.

Clinical signs:

There were no signs of systemic toxicity.

Body weight:

Individual bodyweights and weekly bodyweight changes are given in Table 1.
One female showed bodyweight loss during the first week but expected gain in bodyweight during the second week. One other female showed bodyweight loss during the first and second weeks. The remaining animals showed expected gains in bodyweight over the study period.

Gross pathology:

No abnormalities were noted at necropsy.

Other findings:

Dermal Reactions
Individual dermal reactions are given in Table 2 and Table 3.
Very slight erythema was noted at the test sites of six animals. Small superficial scattered scabs were also noted at the test site of one male. All signs of dermal irritation were fully reversible within 9 days. There were no signs of dermal irritation noted at the test sites of the remaining animals.

Table 1              Individual Bodyweights and Weekly Bodyweight Changes

Dose Level mg/kg	Animal Number and Sex	Bodyweight (g) at Day			Bodyweight Change (g) During Week
		0	7	14	1	2
2504*	1-0 Male	244	265	300	21	35
	3-0 Male	222	250	277	28	27
	3-1 Male	223	249	280	26	31
	3-2 Male	226	247	272	21	25
	3-3 Male	249	287	311	38	24
	2-0 Female	201	195	216	-6	21
	4-0 Female	200	201	204	1	3
	4-1 Female	201	196	195	-5	-1
	4-2 Female	202	211	225	9	14
	4-3 Female	204	208	211	4	3

*= Equivalent to 2000 mg of the anhydrous form of the substance/kg bodyweight

Table 2       Individual Dermal Reactions - Males

Dose Level mg/kg	Animal Number and Sex	Observation	Effects Noted After Initiation of Exposure (Days)
			1	2	3	4	5	6	7	8	9	10	11	12	13	14
2504*	1-0 Male	Erythema Oedema Other	0 0 0	1 0 0	1 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0
	3-0 Male	Erythema Oedema Other	1 0 0	1 0 0	1 0 0	1 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0
	3-1 Male	Erythema Oedema Other	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 Ss	0 0 Ss	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0
	3-2 Male	Erythema Oedema Other	1 0 0	1 0 0	1 0 0	1 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0
	3-3 Male	Erythema Oedema Other	1 0 0	1 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0



* = Equivalent to 2000 mg of the anhydrous form of the substance/kg bodyweight

0 = No reactions Ss = Small superficial scattered scabs

                                                                                       

Table 3       Individual Dermal Reactions – Females

Dose Level mg/kg	Animal Number and Sex	Observation	Effects Noted After Initiation of Exposure (Days)
			1	2	3	4	5	6	7	8	9	10	11	12	13	14
2504*	2-0 Female	Erythema Oedema Other	1 0 0	1 0 0	1 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0
	4-0 Female	Erythema Oedema Other	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0
	4-1 Female	Erythema Oedema Other	1 0 0	1 0 0	1 0 0	1 0 0	0 0 0	0 0 0	1 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0
	4-2 Female	Erythema Oedema Other	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0
	4-3 Female	Erythema Oedema Other	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0	0 0 0

* = Equivalent to 2000 mg of the anhydrous form of the substance/kg bodyweight 0 = No reactions

Interpretation of results:

other: The acute dermal median lethal dose (LD50) of the test item in the Wistar strain rat was found to be greater than 2504 mg/kg bodyweight (equivalent to 2000 mg of the anhydrous form of the substance/kg bodyweight).

Conclusions:

The acute dermal median lethal dose (LD50) of the test item in the Wistar strain rat was found to be greater than 2504 mg/kg bodyweight (equivalent to 2000 mg of the anhydrous form of the substance/kg bodyweight).

Executive summary:

The study was performed to assess the acute dermal toxicity of the test item in the Wistar strain rat. The method was designed to be compatible with the following: OECD Guidelines for the Testing of Chemicals No. 402 "Acute Dermal Toxicity" (adopted 24 February 1987) Method B3 Acute Toxicity (Dermal) of Commission Regulation (EC) No. 440/2008. Initially, two animals (one male and one female) were given a single, 24 hour, semi‑occluded dermal application of the test item to intact skin at a dose level of 2504 mg/kg bodyweight (equivalent to 2000 mg of the anhydrous form of the substance/kg bodyweight). Based on the results of the initial test, a further group of eight animals (four males and four females) was similarly treated. Clinical signs and bodyweight development were monitored during the study. All animals were subjected to gross necropsy.

There were no deaths. There were no signs of systemic toxicity. Very slight erythema was noted at the test sites of six animals. Small superficial scattered scabs were also noted at the test site of one male. All signs of dermal irritation were fully reversible within 9 days. There were no signs of dermal irritation noted at the test sites of the remaining animals. One female showed bodyweight loss during the first week but expected gain in bodyweight during the second week. One other female showed bodyweight loss during the first and second weeks. The remaining animals showed expected gains in bodyweight over the study period. No abnormalities were noted at necropsy.

The acute dermal median lethal dose (LD₅₀) of the test item in the Wistar strain rat was found to be greater than 2504 mg/kg body weigh (equivalent to 2000 mg of the anhydrous form of the substance/kg bodyweight).

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

discriminating dose

Value:

2 000 mg/kg bw

Quality of whole database:

Reliable without restrictions - well performed GLP and OECD guideline study.
Remark: The test item Manganese Oxalate, dihydrate was tested at the limit dose of 2504 mg/kg bw., which is equivalent to 2000 mg/kg bw. of the submission substance (Manganese Oxalate, anhydrous form) resulting in an LD50 value of >2000 mg of the submission substance per kg bw..

Additional information

Justification for selection of acute toxicity – oral endpoint
only one study available

Justification for selection of acute toxicity – dermal endpoint
only one study available

Justification for classification or non-classification

LD50 values derived from acute dermal and oral toxicity studies were greater than 2000 mg/kg bw.. Since these findings do not meet the criteria for classification as acutely toxic according to the rules laid down in Directive 67/548/EEC and in Regulation (EC) No 1272/2008, classification is not warrantable.