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Toxicological information

Acute Toxicity: oral

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Administrative data

Endpoint:
acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2010-04-07 to 2010-05-11.
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study conducted to GLP and to current guideline.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 420 (Acute Oral Toxicity - Fixed Dose Method)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.1 bis (Acute Oral Toxicity - Fixed Dose Procedure)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Test type:
fixed dose procedure
Limit test:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Sponsor's identification: Mn(NO3)2 • 4H2O
Description : pink solid
Batch number : not supplied
Date received : 19 November 2009
Expiry date : not supplied
Storage conditions: approximately 4°C in the dark over silica gel

Test animals

Species:
rat
Strain:
Wistar
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Female Wistar (HsdRccHan:WIST) strain rats were supplied by Harlan Laboratories UK Limited, Bicester, Oxon, UK.
- Age at study initiation: Eight to twelve weeks.
- Weight at study initiation: 153 - 189 g. The bodyweight variation did not exceed ± 20% of the initial/mean bodyweight of any previously dosed animal(s).
- Fasting period before study: Overnight fast immediately before dosing and for approximately three to four hours after dosing.
- Housing: The animals were housed in groups of up to four in suspended solid floor polypropylene cages furnished with woodflakes.
- Diet : Free access to food (2014 Teklad Global Rodent diet supplied by Harlan Teklad, Blackthorn, Bicester, Oxon, UK) was allowed throughout the study.
- Water : Free access to mains drinking water was allowed throughout the study.
- Acclimation period: At least five days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): Temperature set to achieve limits of 19 to 25°C.
- Humidity (%): Relative humidity set to achieve limits of 30 to 70%.
- Air changes (per hr): At least fifteen changes per hour.
- Photoperiod (hrs dark / hrs light): Lighting was controlled by a time switch to give twelve hours continuous light (06:00 to 18:00) and twelve hours darkness.

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
water
Details on oral exposure:
VEHICLE
- Concentration in vehicle: 280.4 mg/ml and 42.1 mg/ml


MAXIMUM DOSE VOLUME APPLIED: 10 ml/kg

DOSAGE PREPARATION (if unusual): For the purpose of the study the test material was freshly prepared, as required, as a solution in distilled water.
The test material was formulated within two hours of being applied to the test system. It is assumed that the formulation was stable for this duration.


- Rationale for the selection of the starting dose: Using available information on the toxicity of the test material, 2804 mg/kg (equivalent to 2000 mg active ingredient/kg bodyweight) was chosen as the starting dose.
Doses:
Dose levels of 2804 mg/kg (equivalent to 2000 mg active ingredient/kg bodyweight) and 421 mg/kg (equivalent to 300 mg active ingredient/kg bodyweight).
No. of animals per sex per dose:
A single female was treated at a dose level of 2804 mg/kg (equivalent to 2000 mg active ingredient/kg bodyweight).
Five females were treated at a dose level of 421 mg/kg (equivalent to 300 mg active ingredient/kg bodyweight).
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Clinical observations were made ½, 1, 2, and 4 hours after dosing and then daily for up to fourteen days. Morbidity and mortality checks were made twice daily. Individual bodyweights were recorded on Day 0 (the day of dosing) and on Days 7 and 14 or at death.
- Necropsy of survivors performed: yes.
Statistics:
Using the mortality data obtained, an estimate of the acute oral median lethal dose (LD50) of the test material was made.

Results and discussion

Preliminary study:
Dose Level - 2804 mg/kg (equivalent to 2000 mg active ingredient/kg bodyweight):

Individual clinical observations and mortality data are given in Table 1.

Mortality:
The animal was killed for humane reasons two hours after dosing, due to the approach of the moderate severity limit set by the UK Home Office.

Clinical Observations:
Signs of systemic toxicity noted were hunched posture, lethargy, tiptoe gait, abdominal discomfort and pilo erection.

Bodyweight:
The bodyweight on Day 0 and at death are given in Table 2.

Necropsy:
Necropsy findings are given in Table 3.
Abnormalities noted at necropsy of the animal treated at a dose level of 2804 mg/kg (equivalent to 2000 mg active ingredient/kg bodyweight) were patchy pallor of the liver, pale kidneys and severe haemorrhage of the gastric mucosa.

Based on the results at a dose level of 2804 mg/kg, a dose level of 421 mg/kg bodyweight was investigated.
Effect levels
Sex:
female
Dose descriptor:
LD50
Effect level:
> 300 mg/kg bw
Based on:
test mat.
Remarks:
anhydrous equivalent
Mortality:
Dose Level - 421 mg/kg (equivalent to 300 mg active ingredient/kg bodyweight):
There were no deaths.
At 2804 mg/kg (equivalent to 2000 mg active ingredient/kg bodyweight, the single female rat tested had to be humanely killed.
Individual clinical observations and mortality data are given in Table 4.
Clinical signs:
Dose Level - 421 mg/kg (equivalent to 300 mg active ingredient/kg bodyweight):
No signs of systemic toxicity were noted during the observation period.
Body weight:
Dose Level - 421 mg/kg (equivalent to 300 mg active ingredient/kg bodyweight):
Individual bodyweights and bodyweight changes are given in Table 5.
All animals showed expected gains in bodyweight over the observation period.
Gross pathology:
Dose Level - 421 mg/kg (equivalent to 300 mg active ingredient/kg bodyweight):
Individual necropsy findings are given in Table 6.
No abnormalities were noted at necropsy.

Any other information on results incl. tables

Table 1              Individual Clinical Observations and Mortality Data -2804 mg/kg

Dose Level mg/kg

Animal Number and Sex

Effects Noted After Dosing
(Hours)

Effects Noted During Period After Dosing
(Days)

½

1

2

4

1

2

3

4

5

6

7

8

9

10

11

12

13

14

2804+

1-0

Female

HLWt

HLWtAd

HLPWtX*

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


+ =     Equivalent to 2000 mg active ingredient/kg bodyweight)

H=      Hunched posture

L =      Lethargy

Wt =    Tiptoe gait

Ad =    Abdominal discomfort

P =      Pilo‑erection

X* =     Animal was killed for humane reasons due to the approach of the moderate severity limit set by the UK Home Office

Table 2              Individual Bodyweights and Bodyweight Changes -2804 mg/kg

Dose Level

mg/kg

Animal Number and Sex

Bodyweight (g) at Day

Bodyweight (g)
at Death

Bodyweight Gain (g)
During Week

0

7

14

1

2

2804+

1-0 Female

153

-

-

151

-

-


+ =     Equivalent to 2000 mg active ingredient/kg bodyweight)

- = animal dead

Table 3              Necropsy Findings - 2804 mg/kg

Dose Level
mg/kg

Animal Number
and Sex

Time of Death

Macroscopic Observations

2804+

1-0 Female

Humanely Killed Day 0

Liver: patchy pallor

Kidneys: pale

Gastric mucosa: severe haemorrhage


+ =     Equivalent to 2000 mg active ingredient/kg bodyweight)

Table 4              Individual Clinical Observations and Mortality Data - 421mg/kg*

Dose Level mg/kg

Animal Number and Sex

Effects Noted After Dosing
(Hours)

Effects Noted During Period After Dosing
(Days)

½

1

2

4

1

2

3

4

5

6

7

8

9

10

11

12

13

14

421*

2-0

Female

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

3-0

Female

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

3-1

Female

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

3-2

Female

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

3-3

Female

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0


* =     Equivalent to 300 mg active ingredient/kg bodyweight)

0=     No signs of systemic toxicity

Table 5              Individual Bodyweights and Bodyweight Changes - 421mg/kg*

Dose Level

mg/kg

Animal Number
and Sex

Bodyweight (g) at Day

Bodyweight Gain (g) During Week

0

7

14

1

2

421*

2-0 Female

171

184

193

10

9

3-0 Female

156

160

168

4

8

3-1 Female

184

189

200

5

11

3-2 Female

162

167

177

5

10

3-3 Female

189

193

209

4

16


* =     Equivalent to 300 mg active ingredient/kg bodyweight)

Table 6              Individual Necropsy Findings- 421mg/kg*

Dose Level
mg/kg

Animal Number
and Sex

Time of Death

Macroscopic Observations

421*

2-0 Female

Killed Day 14

No abnormalities detected

3-0 Female

Killed Day 14

No abnormalities detected

3-1 Female

Killed Day 14

No abnormalities detected

3-2 Female

Killed Day 14

No abnormalities detected

3-3 Female

Killed Day 14

No abnormalities detected


* =     Equivalent to 300 mg active ingredient/kg bodyweight)

Applicant's summary and conclusion

Interpretation of results:
Category 4 based on GHS criteria
Conclusions:
The acute oral median lethal dose (LD50) of the test material in the female Wistar strain rat is greater than 300 mg/kg bodyweight (Globally Harmonised Classification System - Category 4). The effects seen in the single animal tested at the highest dose are most likely due to the severe local action of the test substance, rather than a true systemic effect.