Bis(ethyl acetoacetato-O1',O3)bis(propan-2-olato)titanium

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

BMDL10

407 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

Testing is not necessary since there is enough evidence on the effects of the main decomposition products on fertility and development to conclude that bis(ethylacetoacetato-O1’,O3”) bis(propan-2-olato)titanium is not toxic to reproduction. As the target substance hydrolyses rapidly (< 10 min) when it comes in contact with water or moisture (Brekelmans, M. J. C., 2013), the intrinsic properties are related to the degradation products. After hydrolysis no significant reaction products other than isopropyl alcohol (IPA), ethyl acetoacetate (EAA) and titanium dioxide (TiO2) exist.

For IPA a two-generation reproductive study characterized the reproductive hazard associated with oral gavage exposure in rats (Bevan et al. 1995 cited in OECD, 2004). This study found that the only reproductive parameter apparently affected by IPA exposure was a statistically significant decrease in male mating index of the F1 males. It is possible that the change in this reproductive parameter was treatment related and significant, although the mechanism of this effect could not be discerned from the results of the study. However, the lack of a significant effect of the female mating index in either generation, the absence of any adverse effect on litter size, and the lack of histopathological findings of the testes of the high-dose males suggest that the observed reduction in male mating index may not be biologically meaningful. Additional support for this conclusion is provided by the fact that most of the females became pregnant. Furthermore, male and female fertility, and female fecundity indices of rats dosed with IPA were not different from those of controls by statistical analysis and were within, or relatively close to, historical control values. Exposure to 1000 mg/kg/day and to a lesser extent 500 mg/kg/day did result in a reduction in postnatal survival in both F1 and F2 litters. Derivation of an appropriate NOAEL for offspring effects was made difficult because of conflicting interpretations of the reductions in postnatal survival for the 500 mg/kg/day treatment group. In order to clarify this issue a benchmark dose (BMD) assessment was conducted for the study’s developmental and reproductive findings (Shipp et al. 1996 cited in OECD, 2004). For the offspring developmental effects, BMD dosages (BMDL5) of 449 and 418 mg/kg/day were estimated for the F1 and F2 generations, respectively. Based upon the decrease in male mating index observations in the P2 males, a BMDL10 of 407 mg/kg/day was estimated for reproductive effects (OECD, 2004).

Furthermore, the information provided in section toxicokinetics demonstrates that IPA is highly and efficiently metabolized and do not present a bioaccumulation risk and as described in section acute toxicity section, IPA has an inherently low acute toxicity potential. Furthermore, IPA has already harmonized classification according to EU regulation No. 1272/2008 (CLP) and it is not classified as toxic to reproduction.

For EAA a reproduction and/developmental screening test according to OECD guideline 421 has been performed (LPT, 1999 cited in European Chemicals Bureau, 2002). No statistically significant effect on reproduction or development was observed in rats at doses up to 1 000 mg/kg bw/day.

Most of the available studies suggest that TiO2 is biologically inert. Furthermore, TiO2 is insoluble in water and most ingested titanium is eliminated unabsorbed (Friberg, L. et al. 1986). Based on this data it was concluded that there is no relevance to evaluate the reproduction toxicity of TiO2 in the chemical safety report.

Short description of key information:
The target substance is hydrolytically unstable with half-life < 10 minutes. Thus, the weight of evidence on the decomposition of bis(ethylacetoacetato-O1’,O3”) bis(propan-2-olato)titanium and on the reproduction toxicity study results of the hydrolysis products indicates that the target substance has no effects on fertility.

Justification for selection of Effect on fertility via oral route:
Hydrolytically unstable substance and therefore properties of developmental toxicity are related to degradation product IPA.

Justification for selection of Effect on fertility via inhalation route:
Hydrolytically unstable substance and therefore properties of developmental toxicity are related to degradation product IPA. Developmental toxicity study for IPA related to oral administration is available.

Justification for selection of Effect on fertility via dermal route:
Not relevant exposure route

Effects on developmental toxicity

Description of key information

The target substance is hydrolytically unstable with half-life < 10 minutes. Thus, the weight of evidence on the decomposition of bis(ethylacetoacetato-O1’,O3”) bis(propan-2-olato)titanium and studies conducted for the decomposition products indicate that this substance has no effects on development.

Link to relevant study records

Reference

Endpoint:

developmental toxicity

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Study period:

not reported

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Data obtained from peer-reviewed publication.

Reason / purpose for cross-reference:

reference to same study

Qualifier:

equivalent or similar to guideline

Guideline:

EPA OTS 798.4900 (Prenatal Developmental Toxicity Study)

GLP compliance:

yes

Remarks:

Conducted in compliance with the Toxic Substances Control Act (TSCA) Good Laboratory Paractices Standards (U.S. EPA, 1989a)

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Inc., Raleigh, NC.
- Age at study initiation: Female rats = 10 weeks of age on Gestational Day 0
- Weight at study initiation: 213.6 - 274.6 g on Gestational Day 0
- Housing: Females were singly housed in solid bottom polycarbonate cages with stainless steel wire lids
- Diet (e.g. ad libitum): #5002 Purina Certified Rodent Chow ad libitum
- Water (e.g. ad libitum): Deionized/filtered tap water ad libitum


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22.2±0.50 °C
- Humidity (%): 59.9%±0.55%
- Air changes (per hr): not reported
- Photoperiod (hrs dark / hrs light): 12 hrs dark/ 12 hrs light

Route of administration:

oral: gavage

Vehicle:

other: deionized/distilled water

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: Study dosing solutions were formulated at 0.0, 80.0, 160.0 and 240.0 mg/mL, corresponding 0.0, 400.0, 800.0 and 1200.0 mg/kg/day at a dosing volume of 5.0ml/kg.

Amount of vehicle: 2ml/kg bw

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Concentration of dosing formulations were confirmed by gas chromatography (Hewlet Packard 5890A), with a 30mm x 0,32mm (i.d) capillary column. All formulations were within 97.1-106% of target concentration

Details on mating procedure:

- Impregnation procedure: Cohoused
- If cohoused:
- M/F ratio per cage: Individual females were placed in the home cage of singly housed males (i.e., 1:1)
- Proof of pregnancy: Sperm in vaginal smear referred to as day 0 of pregnancy

Duration of treatment / exposure:

From day 6 to 15 of gestation

Frequency of treatment:

Daily

Duration of test:

20 days. On gestational day (GD) 0 animals were distributed into groups. Test material was administered during GD 6 through GD 15. On GD 20 maternal animals were euthanized/necropsied and embryo/fetal observations were performed

No. of animals per sex per dose:

A total of 25 females per dose were treated.

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: The doses for the range-finding study in rats were 0, 625, 1250, 2500 mg/kg bw/day, 12 sperm positive dams per group. All dams at 2500mg/kg/day died or were were euthanized moribund by GD13; two dams died at 1250mg/kg/day. Also at 1250 mg/kg/day dams exhibited reduced body weights and weight gain, reduced food consumption, and treatment related clinical signs of toxicity. At 1250mg/kg/day there was a significant decrease in fetal body weight per litter unaccompanied by any external malformations or variations. There was no maternal or developmental toxicity observed at 625mg/kg/day.

- Rationale for animal assignment (if not random): Animals were assigned to treatment groups by a stratified randomization method designed to provide uniform mean body weights across dose groups at the initiation of the study.

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Once daily on Gestational Day 0-5 (prior to dosing period) and on Gestational Day 16-20 (after dosing period) and twice daily, at dosing and 1-2 hours after dosing, throughout the dosing period (Gestational Day 6 through 15).

DETAILED CLINICAL OBSERVATIONS: Yes
- At least once daily

BODY WEIGHT: Yes
- Time schedule for examinations: gestation days 0, 6, 9, 12, 15, 18 and 20.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: not applicable

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 20
- Organs examined: thoracic and abdominal organs and cavities, maternal body, liver and uterus weights recorded.

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes
- Other: dead and live fetuses

Fetal examinations:

- External examinations: Yes: all per litter
- Soft tissue examinations: Yes: all per litter
- Skeletal examinations: Yes: half per litter
- Head examinations: Yes: half per litter

Statistics:

Parametric statistical procedures were applied to selected measures from this toxicity study. Appropriate General Linear Models (GLM) procedures (SAS Institute Inc., 1985a, 1985b) for the proposed Analyses of Variance (ANOVA) were employed. Prior to GLM analysis, an arcsine-square root transformation was performed on all litter-derived percentage data (Snedecor and Cochran, 1967) and Bartlett’s test for homogeneity of variance (alpha level = 0.001) was performed on all data to be analyzed by ANOVA (Winer, 1962). GLM analysis was used to determine the significance of the dose-response relationships (Test for Linear Trend), and to determine whether significant dose effects had occurred for selected measures (ANOVA). When a significant (p<0.05) main effect for dose occurred, Williams’ Multiple Comparison Test (Williams, 1971; 1972) and/or Dunnett’s Multiple Comparison Test (Dunnett, 1955; 1964) was used to compare each exposed group to the vehicle control group for that measure. A one-tailed test (i.e., Williams’ Test and/or Dunnett’s Test) was used for all pairwise comparisons except that a two-tailed test was used for maternal body and organ weight parameters, maternal food consumption, fetal body weight, and percent males per litter. Nominal scale measures were analyzed by Chi-Square Test for Independence for differences among treatment groups, and by a test for linear trend on proportions (Snedecor and Cochran, 1967). When Chi-Square revealed significant (p<0.05) differences among groups, then a one-tailed Fisher’s Exact Probability Test was used for pair wise comparisons between each treated group and the vehicle control group.

Indices:

Dams: pregnancy; corpora lutea; implantation sites per litter; percent preimplantation loss; live fetuses per litter; total and percent: resorptions per litter, litters with resorptions, late fetal deaths per litter, litters with late fetal deaths, adversely affected implants per litter; male and female fetuses per litter; average fetal body weight per litter; average male fetal body weight per litter; and average female fetal body weight per litter.

Historical control data:

The designation of fetal alterations as malformations or variations was based on the literature and on historical control data in the performing laboratory.

Details on maternal toxic effects:

Maternal toxic effects:yes

Details on maternal toxic effects:
No pregnant surviving female aborted, delivered early or was removed from study. Two females (8%) died in the 1200 mg/kg bw/day group and one female (4%) died in the 800 mg/kg bw/day group. Maternal body weights were equivalent across all groups and for all timepoints. The statistically reduced maternal weight gain (Gestational Days 0-20) in the 1,200 mg/kg bw/day group was likely due to significantly reduced gravid uterine weights. Corrected maternal weight gain for Gestational Days 0-20 was statistically equivalent across all groups. There were no treatment related clinical signs apparent in maternal animals. Maternal food consumption was statistically equivalent across all groups for all intervals evaluated although a significant downward trend for Gestational Days 6-9 and 6-15 (treatment period) with no significant pairwise comparisons was evident.

Dose descriptor:

NOAEL

Effect level:

400 mg/kg bw/day (actual dose received)

Based on:

not specified

Basis for effect level:

other: maternal toxicity

Dose descriptor:

NOAEL

Effect level:

400 mg/kg bw/day (actual dose received)

Based on:

not specified

Basis for effect level:

other: developmental toxicity

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
A total of 22-25 litters were evaluated per group. No litter was fully resorbed. All gestational parameters were equivalent across groups, including pre- and post-implantation loss. Fetal body weights/litter were significantly reduced in the 800 and 1,200 mg/kg bw/day groups. There were no treatment-related increased incidences in individual or pooled external, visceral, skeletal or total fetal malformations or variations.

Dose descriptor:

NOAEL

Effect level:

400 mg/kg bw/day (actual dose received)

Sex:

male/female

Basis for effect level:

fetal/pup body weight changes

Remarks on result:

other:

Remarks:

A total of 22-25 litters were evaluated per group. No litter was fully resorbed. All gestational parameters were equivalent across groups, including pre- and post-implantation loss. Fetal body weights/litter were significantly reduced in the 800 and 1,200 mg/kg bw/day groups. There were no treatment-related increased incidences in individual or pooled external, visceral, skeletal or total fetal malformations or variations.

Abnormalities:

not specified

Developmental effects observed:

not specified

Read-across justifications and data matrices are presented in IUCLID section 13.

Conclusions:

Propan-2-ol was not teratogenic when administered orally during GD6-15 to rats. By the publication, the NOAEL for both maternal and developmental toxicity was 400 mg/kg/day.

Executive summary:

Possible prenatal developmental toxicity of propan-2 -ol in rats was evaluated in this study conducted according to U.S EPA guideline 40 CFR 798.4900 under U.S. EPA Good Laboratory Paractice (GLP) Standards.

Time-pregnant rats, 25/group, dosed orally with propan-2 -ol at 0, 400, 800 or 1200mg/kg bw/day, once daily on gestation days 6 throught 15. Clinical observations were made at least once daily throughout the study period. Rats were weighed and food consumption was recorded every 6 or 3 days during gestation. Maternal animals were euthanized at 1 day prior expected parturition and necropsied. Fetuses were examined for external and visceral alterations and in addition soft tissue, skeletal and head examinations were performed.

Oral administration of propan-2 -ol to rats results maternal toxicity including lethality at 800 and 1200 mg/kg/day. Propan-2 -ol administration causes developmental toxicity, expressed as reduced fetal body weights with no indication of treatment-related teratogenicity or increased incidence of variations, at doses which resulted in treatment-related maternal deaths.

Based on test results, the following No Observed Adverse Effect Levels (NOAEL) were derived:

Maternal NOAEL: 400 mg/kg/day

Developmental NOAEL: 400 mg/kg/day

The results of this study would not lead to the classification for reproduction developmental toxicity according to EU Directive 67/548/EEC and EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

400 mg/kg bw/day

Study duration:

subacute

Species:

rat

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no study available

Additional information

There are no developmental toxicity studies available for bis(ethylacetoacetato-O1’,O3”) bis(propan-2-olato)titanium. As the target substance hydrolyses rapidly (< 10 min) when it comes in contact with water or moisture (Brekelmans, M. J. C., 2013), intrinsic properties are related to the degradation products. After hydrolysis no significant reaction products other than isopropyl alcohol (IPA), ethyl acetoacetate (EAA) and titanium dioxide (TiO2) exist. Thus, read-across data from these degradation products is used to complete the endpoint requirements.

Most of the available studies suggest that TiO2 is biologically inert. Furthermore, TiO2 is insoluble in water and most ingested titanium is eliminated unabsorbed (Friberg, L. et al. 1986). Based on this data it was concluded that there is no relevance to evaluate the developmental toxicity of TiO2 in the chemical safety report.

For EAA a reproduction and/developmental screening test according to OECD guideline 421 has been performed (LPT, 1999 cited in EC, 2002). No statistically significant effect on reproduction or development was observed in rats at doses up to 1 000 mg/kg bw/day.

In the following paragraphs the developmental toxicity studies for IPA are discussed. The studies were performed using rats and rabbits and the method followed the EPA OTS 798.4900 (Prenatal Developmental Toxicity Study) guideline (Tyl, R. W. et al. 1994). The rats were dosed by oral gavage at 400, 800 or 1200 mg/kg from gestational days 6 through 15. The rabbits were dosed by oral gavage at 120, 240 or 480 mg/kg from gestational days 6 through 18.

Maternal toxic effects

Rats: No pregnant surviving female aborted, delivered early or was removed from study. Two females (8%) died in the 1200 mg/kg bw/day group and one female (4%) died in the 800 mg/kg bw/day group. Maternal body weights were equivalent across all groups and for all time points. The statistically reduced maternal weight gain (Gestational Days 0-20) in the 1,200 mg/kg bw/day group was likely due to significantly reduced gravid uterine weights. Corrected maternal weight gain for Gestational Days 0-20 was statistically equivalent across all groups. There were no treatment related clinical signs apparent in maternal animals. Maternal food consumption was statistically equivalent across all groups for all intervals evaluated although a significant downward trend for Gestational Days 6-9 and 6-15 (treatment period) with no significant pair wise comparisons was evident. Based on these results, maternal toxicity for rats was 400mg bw/day.

Rabbits: Profound maternal toxicity at 480 mg/kg/day, expressed as 26.7% mortality, reduced body weight gain during the treatment period and for the gestational period corrected for the contribution of the gravid uterus, reduced food consumption during the treatment period and relatively severe clinical signs of toxicity. At 240 and 120 mg/kg/day, the only findings were transient, relatively mild and nonspecific clinical signs of toxicity. Thus, the maternal toxicity NOAEL for rabbits was concluded to be 240 mg/kg bw/day.

Teratogenic effects

Rats: A total of 22-25 litters were evaluated per group. No litter was fully resorbed. All gestational parameters were equivalent across groups, including pre- and post-implantation loss. Fetal body weights/litter were significantly reduced in the 800 and 1,200 mg/kg bw/day groups. There were no treatment-related increased incidences in individual or pooled external, visceral, skeletal or total fetal malformations or variations. The developmental NOAEL was concluded to be 400 mg/kg bw/day for rats.

Rabbits: There was no demonstrable developmental toxicity at a dose resulting in significant maternal toxicity (480 mg/kg/day) or at doses with only relatively mild and transient clinical signs of toxicity (240 and 120 mg/kg/day). Thus, based on these results the developmental NOAEL for rabbits was 480 mg/kg bw/day.

IPA has also been tested for developmental toxicity in rats via oral gavage (Bates, H. K. et al. 1994). The rats were dosed at 200, 700 and 1200 mg/kg from gestational days 6 through 21. No exposure-related effects were noted on motor activity, weights of the four regions of the brain, developmental landmarks, or morphological changes to the tissues of the central nervous tissue. These data suggest the developmental neurotoxicity NOAEL for rats is 1200 mg/kg.

Justification for selection of Effect on developmental toxicity: via oral route:
Selected based on the lowest developmental NOAEL.

Justification for selection of Effect on developmental toxicity: via inhalation route:
Hydrolytically unstable substance and therefore properties of developmental toxicity are related to degradation product IPA. Developmental toxicity study for IPA related to oral administration is available.

Justification for selection of Effect on developmental toxicity: via dermal route:
Not relevant exposure route.

Justification for classification or non-classification

The weight of evidence on decomposition of the target substance and the studies available from the most hazardous decomposition product, (IPA), indicate that there is currently no need for classification of bis(ethylacetoacetato-O1’,O3”) bis(propan-2-olato)titanium concerning toxicity for reproduction or teratogenicity according to the CLP Regulation (EC) 1272/2008 and EU Directive 67/548/EEC.