Formaldehyde

Developmental toxicity / teratogenicity

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)

1

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

2

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).