Thionyl dichloride

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

other: read-across from the hydrolysis product of SOCl2 (SO2)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: scientifically acceptable and sufficient documented

Data source

Reference

Reference Type:

publication

Title:

Behavioural disturbances in adult CD-1 mice and absence of effects on their offspring upon SO2 exposure

Author:

Petruzzi s, Dell'Omo G, Fiore M, Chiarotti F, Bignami G, Alleva E

Year:

1996

Bibliographic source:

Arch Toxicol 70: 757-766

Materials and methods

Principles of method if other than guideline:

Adult male and female CD-1 mice were exposed to different SO2 coencentrations (0, 5, 12, or 30 ppm) for 24 days before the formation of breeding pairs to pregnancy day 12-14. This exposure was near-continuous, covering about 80% of the total time indicated.

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Sulphur dioxide

EC Number:

231-195-2

EC Name:

Sulphur dioxide

Cas Number:

7446-09-5

Molecular formula:

O2S

IUPAC Name:

oxosulfane oxide

Test material form:

other: gaseous

Details on test material:

S02 was delivered from 40-liter aluminium bottles (5100- 5150 ppm, 150 Bar; Caracciolossigeno, 1-00155 Rome, Italy). Different SO2 concentrations were obtained by varying the flow and gas pressure from the bottles.

Test animals

Species:

mouse

Strain:

CD-1

Administration / exposure

Route of administration:

inhalation: gas

Type of inhalation exposure (if applicable):

whole body

Vehicle:

air

Analytical verification of doses or concentrations:

yes

Details on mating procedure:

Ten breeding pairs were formed in each chamber on the morning of ED 9, shortly after the last activity lest. Fernales were inspected daily for the presence of a vaginal plug (pregnancy day 0, which corresponded to ED 10-12, depending upon the time of maling) and for delivery (PND 1), the males being removed on pregnancy day 12. At birth, all Iittcrs were culled to four males and four females and fostered to untreated dams, which had given birth to healthy Iitters within the previous 24 h.

Duration of treatment / exposure:

24 days

Frequency of treatment:

near-continuous (covering about 80% of the total time indicated (24 days)

Duration of test:

24 days

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 5, 12, or 30 ppm)
Basis:
nominal conc.

No. of animals per sex per dose:

10 per sex per dose

Control animals:

yes, concurrent vehicle

Results and discussion

Results: maternal animals

Effect levels (maternal animals)

Dose descriptor:

NOAEC

Effect level:

>= 30 ppm

Based on:

test mat.

Basis for effect level:

other: other:

Results (fetuses)

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Fetal abnormalities

Abnormalities:

not specified

Overall developmental toxicity

Developmental effects observed:

not specified

Any other information on results incl. tables

SO2 exposure at any concentration did not affect mating (100%) in all groups), proportion of successful pregancies (100% in all groups), litter size, sex ratio, or neonatal mortality (1, 0, 2, and 1 nonviable litters in the 0, 5, 12, and 30 ppm groups, respectively, including failures of the cross-forsting procedure). Reproductive performance as well as postnatal somatic and neurobehavioural development of the offspring (the latter assessed by an observational test battery including eight reflexes and responses) were not affected by SO2 (Petruzzi S et al., Behavioural disturbances in adult CD-1 mice and absence of effects on their offspring upon SO2 exposure, Arch Toxicol (1996) 70: 757 -766).

Applicant's summary and conclusion

Executive summary:

Adult male and female CD-1 mice were exposed to different SO2 coencentrations (0, 5, 12, or 30 ppm) for 24 days before the formation of breeding pairs to pregnancy day 12-14. This exposure was near-continuous, covering about 80% of the total time indicated.

The absence of effects on reproductive performance and neurobehavioural development of the offspring suggests that the risk to the developing organism from gestational exposure is low.