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Toxicological information

Developmental toxicity / teratogenicity

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Administrative data

Endpoint:
developmental toxicity
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
3 (not reliable)
Rationale for reliability incl. deficiencies:
other: Dose-range-finding teratology study; only 6 dams per dose level

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1985
Report Date:
1985

Materials and methods

Principles of method if other than guideline:
Dose-range-finding teratology study in rats
GLP compliance:
no
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
gas
Specific details on test material used for the study:
Paraformaldehyde
Batch No. 732540 from Fischer Scientific Co.
The purity of is at least 95%, with the majority of the remaining 5% being water

Test animals

Species:
rat
Strain:
Sprague-Dawley

Administration / exposure

Route of administration:
inhalation: gas
Type of inhalation exposure (if applicable):
whole body
Vehicle:
air
Details on exposure:
Formaldehyde gas was generated by depolymerizing paraformaldehyde at constant temperature (80°C)
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Daily samples were analyzed by the chromotropic acid method
Details on mating procedure:
Mating was achieved by placing 1 female with 1 male overnight; mating determined by the presence of spermatozoa in the vaginal lavage; the day
of positive identification of spermatozoa termed day 0 of gestation.
Duration of treatment / exposure:
day 6 to day 15 of gestation
Frequency of treatment:
once daily; 6 hours/day
Duration of test:
Sacrifice and caesarean section day 20 of gestation
No. of animals per sex per dose:
6
Control animals:
yes, sham-exposed

Examinations

Maternal examinations:
Clinical signs
Mortality
Body weight
Food consumption
Necropsy
Ovaries and uterine content:
corpora lutea, live and dead fetuses, early, middle and late resorptions and the pre- and post-implantation losses

Results and discussion

Results: maternal animals

Effect levels (maternal animals)

open allclose all
Dose descriptor:
LOAEC
Effect level:
10 ppm (nominal)
Basis for effect level:
clinical signs
body weight and weight gain
food consumption and compound intake
necropsy findings
Dose descriptor:
NOAEC
Effect level:
5 ppm (nominal)

Maternal abnormalities

Abnormalities:
effects observed, treatment-related
Localisation:
other: red nasal discharge, red nasal discharge, decreased body weight, reduced food consumption

Results (fetuses)

Effect levels (fetuses)

Dose descriptor:
NOAEC
Effect level:
16 ppm (nominal)
Based on:
test mat.
Basis for effect level:
other: highest dose level tested; limited parameters measured

Fetal abnormalities

Abnormalities:
no effects observed

Overall developmental toxicity

Developmental effects observed:
no

Applicant's summary and conclusion

Conclusions:
In a pilot study for range-finding no developmental effects were detected in an inhalation study in rats at the high dose level of 16 ppm but maternal toxicity at >= 10 ppm (NOAEC 5 ppm).