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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:
key study
Study period:
16.03.1994 to 22.04.1994
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: A GLP compliant study undertaken to a standard considered to be equivalent to international test guidelines for a developmental toxicity study .
Cross-reference
Reason / purpose for cross-reference:
reference to same study

Data source

Referenceopen allclose all

Reference Type:
study report
Title:
Unnamed
Year:
1994
Report date:
1994
Reference Type:
publication
Title:
Developmental toxicity of di-isodecyl and di-isononyl phthalates in rats.
Author:
Waterman SJ, Ambroso JL, Keller LH, Trimmer GW, Nikiforov AI, Harris SB.
Year:
1999
Bibliographic source:
Reprod Toxicol 13:1-6

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 414 (Prenatal Developmental Toxicity Study)
Deviations:
no
Principles of method if other than guideline:
There is no explicit statement in the report that the study was undertaken in accordance with a specific guideline, although there are references to the US EPA 'Test guidelines for developmental toxicity' and the EU Annex V methods for the determination of toxicity, 'Teratogenicity '
GLP compliance:
yes
Limit test:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
1,2-Benzenedicarboxylic acid, di-C8-10-branched alkyl esters, C9-rich
EC Number:
271-090-9
EC Name:
1,2-Benzenedicarboxylic acid, di-C8-10-branched alkyl esters, C9-rich
Cas Number:
68515-48-0
Molecular formula:
C26 H42 O4
IUPAC Name:
1,2-Benzenedicarboxylic acid, di-C8-10-branched alkyl esters, C9-rich
Constituent 2
Reference substance name:
DINP
IUPAC Name:
DINP
Details on test material:
- Name of test material (as cited in study report): Di-isononyl phthalate
- Substance type: Technical material
- Physical state: Colourless liquid
- Stability under test conditions: No data
- Storage condition of test material: Room temperature

Test animals

Species:
rat
Strain:
Sprague-Dawley
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Charles River Laboratories Inc.
- Age at study initiation: Approximately 10 weeks
- Weight at study initiation: 212 to 270g
- Fasting period before study: No
- Housing: Single, except during mating, in suspended stainless steel cages, with wire mesh and absorbent paper below.
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 15 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 to 24.4 °C
- Humidity (%): 40-70% RH
- Air changes (per hr): No data
- Photoperiod (hrs dark / hrs light): 12 hours dark/12 hours light


IN-LIFE DATES: From: 12 March 1994 To: 22 April 1994

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
corn oil
Details on exposure:
PREPARATION OF DOSING SOLUTIONS:
-The undiluted test material was thoroughly mixed in carrier (corn oil) prior to dispensing. The test material/carrier mixture was prepared weekly. The test material was soluble in the carrier at the conentrations required for this study.



VEHICLE
- Justification for use and choice of vehicle (if other than water): No data
- Concentration in vehicle: Nominal, 20, 100 or 200 mg/ml
- Amount of vehicle (if gavage): 5 ml/kg
- Lot/batch no. (if required):DEC1594B, DEC1494B
- Purity: No data
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
The stability and homogeneity of the test material in corn oil was demonstrated by the testing laboratory before or at the start of treatment. Homogeneity was investigated at 0.8% and 20% w/v. The coefficient of variance ranged from 0 to 0.820%, indicating excellent uniformity. Stability was confirmed for 8 days at room temperature. The concentrations of test material in the carrier were checked for Weeks 1 and 3, and were all within 8% of nominal concentrations.
Details on mating procedure:
- Impregnation procedure: co-housed
- M/F ratio per cage: 1:1
- Length of cohabitation: Overnight
- Verification of same strain and source of both sexes: yes
- Proof of pregnancy: vaginal plug/sperm in vaginal smear referred to as Day 0 of pregnancy
- Any other deviations from standard protocol: No
Duration of treatment / exposure:
Gestation Day 6 through Day 15
Frequency of treatment:
Daily
Duration of test:
One month
Doses / concentrations
Remarks:
Doses / Concentrations:
0 (Control), 100, 500 and 1000 mg/kg/day
Basis:
nominal conc.
No. of animals per sex per dose:
25
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: No data
- Rationale for animal assignment (if not random): Females were assigned to dose groups in the order of mating

Examinations

Maternal examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Twice daily during the treatment period and once daily at other times.


DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: females daily during gestation

BODY WEIGHT: Yes
- Time schedule for examinations: Gestation Day 0, 6, 9, 12, 15, 18 and 21


FOOD CONSUMPTION : Yes
- Food consumption for each female concurrently with bodyweight.


WATER CONSUMPTION: No


POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 21
- Organs examined: Uterus


Ovaries and uterine content:
The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes (with ovaries)
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes
- Other: Live, dead and externally malformed fetuses counted
-Uteri of apparently non-pregnant dams: stained to confirm pregnancy status.
Fetal examinations:
- External examinations: Yes: all per litter
- Soft tissue examinations: Yes: half per litter
- Skeletal examinations: Yes: half per litter
- Head examinations: Yes: half per litter
Statistics:
Reported in the 'any other information on materials and methods' field below.

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:
Maternal toxic effects:yes

Details on maternal toxic effects:
Statistically significant mean bodyweight gain suppression and reduction in mean food consumption were observed in the high dose female animals compared with controls during the treatment period (GD 6-15)

Effect levels (maternal animals)

open allclose all
Dose descriptor:
NOAEL
Effect level:
500 mg/kg bw/day
Basis for effect level:
other: maternal toxicity
Dose descriptor:
NOAEL
Effect level:
1 000 mg/kg bw/day
Basis for effect level:
other: developmental toxicity

Results (fetuses)

Details on embryotoxic / teratogenic effects:
Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
There were no statistically significant differences in mean fetal bodyweight and no statistically significant increases in total or individual external, visceral or skeletal malformations between treated and control animals.

There were several statistically significant increases in the incidences of fetal variation both on an individual and litter basis in the treated groups compared with the controls. However, all of these incidences were within the historic control range of the laboratory or were regarded as alternative normal patterns and were not regarded as harmful developmental effects . These diffences are tabulated in the results section below.

Effect levels (fetuses)

open allclose all
Dose descriptor:
NOAEL
Effect level:
1 000 mg/kg bw/day
Basis for effect level:
other: teratogenicity
Dose descriptor:
NOAEL
Effect level:
1 000 mg/kg bw/day
Basis for effect level:
other: embryotoxicity
Remarks on result:
not determinable
Remarks:
no NOAEL identified

Fetal abnormalities

Abnormalities:
not specified

Overall developmental toxicity

Developmental effects observed:
not specified

Any other information on results incl. tables

Statistically significant increases in fetal variations from controls were as follows:

Fetal parameter

Dose mg/kg

Fetal incidence (%)

Litter incidence (%)

Historical control range (%)

Total with visceral variations

0

0.5

4.3

1.1-29.1 F

100

3.7*

12.0

500

4.0*

16.7

4.4-72.2 L

1000

5.1**

30.4*

Dilated renal pelvis

0

0.0

0.0

1.1-12.6 F

100

3.7**

12.0**

500

4.0**

16.7**

4.4-37.5 L

1000

4.5**

26.1**

Total with skeletal variations

0

16.8

62.5

29.8-57.8 F

100

15.0

64.0

500

28.4**

91.7*

76.0-100.0L

1000

43.7**

87.0

Rudimentary lumbar ribs

0

3.7

25.0

3.8-21.6F

100

5.4

20.0

500

18.6**

54.2

29.2-61.9L

1000

34.5**

78.3**

Rudimentary cervical ribs

0

1.6

12.5

0.0-4.0F

100

1.6

12.0

500

1.0

8.3

4.3-16.7 L

1000

5.7*

30.4

*Statistically significant p= 0.05 (Fisher exact test)              F on a per Fetus basis

** Statistically significant p= 0.01(Fisher exact test)             L on a per Litter basis

There was a dose-related increase in total fetuses with visceral and skeletal variations on a per fetus basis and a dose-related increase in total fetuses with skeletal variations on a per litter basis. Statistically significant increases in total fetuses with visceral variations were observed in all treated groups when compared with controls. The high dose group also was statistically significant on a per litter basis. Statistically significant increases in total fetuses with skeletal variations were observed in the mid and high dose groups when compared with controls. The mid dose group also was statistically significantly increased for skeletal variations on a per litter basis.

Statistically significant increases in dilated renal pelves were observed in all treated groups when compared with controls on a per fetus basis and in the high dose group when compared with controls on a per litter basis. The increase in dilated renal pelves on a per fetus basis occurred in a dose­related fashion. Rudimentary lumbar 'ribs were significantly increased (p0.01) in the mid and high dose groups when compared with controls on a per fetus basis and in the high dose group when compared with controls on a per litter basis. These increases occurred in a dose-related fashion on both a per fetus and litter basis. A statistically significant increase in fetuses with rudimentary cervical ribs also was observed in the high dose group when compared with controls.

Applicant's summary and conclusion

Conclusions:
Maternal toxicity was evident at 1000 mg/kg/day, as suppression of bodyweight gain and reduced food consumption during the dosing period. Signs of embryotoxicity were not apparent. Accordingly, the maternal NOAEL was established as 500 mg/kg/day and the developmental NOAEL was established as 1000 mg/kg/day. The results indicated that DINP was not a selective developmental toxicant and was not embryotoxic or teratogenic under the conditions of this study.
Executive summary:

In this developmental toxicity study, mated female rats received di-isononyl phthalate (DINP) at dosages of 0 (vehicle control), 100, 500 or 1000 mg/kg b.w./day), once daily by oral gavage, from gestation Day 6 through 15.

Maternal toxicity was evident at 1000 mg/kg/day, as suppression of bodyweight gain and reduced food consumption during the dosing period. Signs of embryotoxicity were not apparent. Accordingly, the maternal NOAEL was established as 500 mg/kg/day and the developmental NOAEL was established as 1000 mg/kg/day. The results indicated that DINP was not a selective developmental toxicant and was not embryotoxic or teratogenic under the conditions of this study.

The toxicity study is considered acceptable for classification, and satisfies the guideline requirements for rat developmental toxicity studies.