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Toxicological information

Toxicity to reproduction: other studies

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Administrative data

Endpoint:
toxicity to reproduction: other studies
Type of information:
experimental study
Adequacy of study:
other information
Study period:
no data
Reliability:
2 (reliable with restrictions)
Cross-referenceopen allclose all
Reason / purpose for cross-reference:
reference to same study
Reason / purpose for cross-reference:
reference to other study

Data source

Reference
Reference Type:
publication
Title:
Effects of chlorine dioxide on neurobehavioral development of rats. In: Jolley RL, Bull RJ and Davis WP (eds) Water chlorination: Chemistry, environmental impact and health effects.
Author:
Taylor DH and Pfohl RJ
Year:
1985
Bibliographic source:
Lewis Publishers, Inc. Chelsea, MI, Vol 5: 355-364

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Pups were exposed from postnatal day 5 to 20
GLP compliance:
not specified
Type of method:
in vivo

Test material

Constituent 1
Reference substance name:
10047-04-4
IUPAC Name:
10047-04-4
Constituent 2
Chemical structure
Reference substance name:
Chlorine dioxide
EC Number:
233-162-8
EC Name:
Chlorine dioxide
Cas Number:
10049-04-4
Molecular formula:
ClO2
IUPAC Name:
Chlorine dioxide generated from sodium chlorate and hydrogen peroxide in the presence of a strong acid
Details on test material:
no data

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Age at study initiation: new litter (5 days old)
No other data

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
not specified
Details on exposure:
no data
Analytical verification of doses or concentrations:
not specified
Details on analytical verification of doses or concentrations:
no data
Duration of treatment / exposure:
from 5d through 20d of age
Frequency of treatment:
daily
Duration of test:
until postnatal day 60
Doses / concentrations
Remarks:
Doses / Concentrations:
14 mg/kg/day
Basis:
actual ingested
No. of animals per sex per dose:
8 males per litter (from unexposed dams)
Control animals:
yes, concurrent vehicle
Details on study design:
Locomotor activity was performed.
On day 11 or 21 post partum, some rats were decapitated. Cerebellum (minus the paraflocculi) and forebrain (minus olfactory lobes) were removed and weighed and DNA was extracted.
The behaviour of 28 and 60 day old rats was examined in an open field apparatus during a 15 minute sampling period.
Statistics:
no data

Results and discussion

Effect levels

Dose descriptor:
LOAEL
Effect level:
14 mg/kg bw/day
Based on:
not specified
Sex:
male
Basis for effect level:
other: decreased activity, decreased brain weight and DNA content

Observed effects

Only male pups (8 per litter) were examined for selected neurodevelopmental endpoints.
*Pup body weight: significantly decreased at PND 21
* Exploratory behavior measured: decreased on PND 60, but not on PND 28
* Locomotor activity measured from PND 5 to 20 (measurement per litter) and from PND 50 to 60 (individual measurement): decrease on PND 18-19 and contradictory results at PND 50-60.
* DNA contents: the total DNA contents of both the cerebellum and forebrain were significantly reduced

These data indicate that rat pups exposed to ClO2 post-natally from day 5 to day 20 of age, exhibited behavioural deficits and depressed brain growth, consistent with effects produced by depressed thyroid function.

Any other information on results incl. tables

No other information

Applicant's summary and conclusion

Conclusions:
LOAEL was determined to be 14 mg/kg bw/day.
Executive summary:

Chlorine dioxide was administered to Spague-Dawley pups rats by oral gavage at dose level of 14 mg/kg bw/day during postnatal day 5 through 20.

Only male pups (8 per litter) were examined for selected neurodevelopmental endpoints.

Pup body weight was significantly decreased at PND 21 by direct exposure. Exploratory behavior measured on PND 28 and 60 showed decreased in both way of exposure.

Locomotor activity measured from PND 5 to 20 (measurement per litter) and from PND 50 to 60 (individual measurement) showed a decrease on PND 18-19 and contradictory results at PND 50-60.
The total DNA content of the cerebella was significantly reduced for both the cerebellum and forebrain.

These data indicate that rat pups exposed to ClO2 both exhibited behavioral deficits and depressed brain growth, consistent with effects produced by depressed thyroid function.

LOAEL was determined to be 14 mg/kg bw/day.