Silicomanganese manufacturing fumes dedusting solid residues

Toxicity to reproduction

Administrative data

Endpoint:

toxicity to reproduction

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Not conducted to GLP, standard observations not made. Focus is on haematology and effect of Mn in rats maintained on low-Fe diets.

Data source

Reference

Reference Type:

publication

Title:

Chronic manganese oxide ingestion in rats: hematological effects

Author:

Carter SD, Hein JF, Rehnberg GL and Laskey JW

Year:

1980

Bibliographic source:

J. Toxicol. Environ. Health, 6(1): 207-216

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

The haematological effects of chronic Mn3O4 exposure during both prenatal and postnatal periods was determined. Data was obtained from the parental to F2 generations. Effects of exposure to Mn3O4 during Fe deficiency were determined by placing half of the animals of a low Fe diet and the other half on a normal diet.
STUDY 1: Rats (known to be at gestation day 1) were randomly assigned to 8 treatment groups. Treatment began on gestational day 2 and was continued in the F1 generation through 244 d of age.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Silicomanganese manufacturing fumes dedusting solid residues

EC Number:

930-776-4

IUPAC Name:

Silicomanganese manufacturing fumes dedusting solid residues

Test animals

Species:

rat

Strain:

Long-Evans

Sex:

male/female

Administration / exposure

Route of administration:

oral: feed

Type of inhalation exposure (if applicable):

not specified

Vehicle:

not specified

Details on exposure:

Mean particle diameter:
STUDY 1: 0.62 µm (range 0.1 - 2.8 µm), 80% of particles evaluated were <1 µm in diameter.
STUDY 2: 1.2 µm (range: 0.1-5.6 µm), 45% of total particles were <1µm in diameter.

Details on mating procedure:

STUDY 1: Animals were received at day 1 of gestation.
STUDY 2: Animals were received when pregnant.

Analytical verification of doses or concentrations:

yes

Duration of treatment / exposure:

STUDY 1: treatment continued from day 2 of gestation to day 224 of age (F1 generation)
Study 2: treatment continued through pregnancy to day 40 of age (F1 generation).

Frequency of treatment:

Daily

Doses / concentrations

Remarks:

Doses / Concentrations:
400, 1100 and 3550 ppm Mn
Basis:

No. of animals per sex per dose:

No data

Control animals:

yes

Results and discussion

Overall reproductive toxicity

Reproductive effects observed:

not specified

Any other information on results incl. tables

Study 1:

Red Blood Cell count, Haematocrit and Mean cell volume values of animals maintained on normal Fe diets differed significantly from animals maintained on low-Fe diets.

Mortality: mortality rate was increased (>50%) in animals at the highest dose group (low-Fe), from birth to 40 d of age. Consequently all remaining animals in this group were killed at day 40. All blood values were significantly lower than the control animals on the low-Fe diet.

Haematocrit values in the low-Fe groups was depressed from 24 to 100 days of age. There were no evident Mn dose responses.

A strong correlation between dietary Fe levels and certain serum constituents was noted at both 100 and 200 days of age.

Bodyweights and food consumption: A significant dose-related decrease in bodyweight was seen at days 52 and 88. animals receiving the low-Fe diet consumed more food than the controls. This was not significant.

Study 2:

No significant Mn -related effects.

Applicant's summary and conclusion

Conclusions:

Low -Fe diet animals were more sensitive to Mn exposure.