Registration Dossier

Administrative data

Endpoint:
extended one-generation reproductive toxicity - basic test design (Cohorts 1A, and 1B without extension)
Type of information:
experimental study planned
Study period:
Dependent upon feedback from ECHA
Justification for type of information:
Considerations that the general adaptation possibilities of Annex XI of the REACH Regulation are not adequate to generate the necessary information
• There are no available GLP studies for reproductive toxicity

No GLP studies on the substance are available for the endpoint ‘reproductive toxicity’.
• There are no available non-GLP studies for reproductive toxicity

No non-GLP studies are available for the endpoint ‘reproductive toxicity’.
• historical human data
No human data suggesting reproductive toxicity are available for this substance.
• (Q)SAR

No validated (Q)SAR’s exist for this endpoint.
• in vitro methods

In accordance with ECHA’s guidance on the information requirements and chemical safety assessment, chapter R7a., the regulatory acceptance of in vitro studies for reproductive toxicity and approaches to replace the animal testing for reproductive toxicity has not been achieved as they do not provide equivalent information and thus, cannot be used alone for classification and labelling and/or risk assessment.
• weight of evidence

Insufficient reliable data are available to complete the IUCLID requirements as a weight of evidence approach.
• grouping and read-across

There are no other substances that are suitable for read-across or grouping.

Not applicable – wide-dispersive use of substance cannot be excluded.
Considerations that the specific adaptation possibilities of Annexes VI to X (and column 2 thereof) were not applicable:
Adaptation options as defined in Annexes VI to X were not applicable for this substance and this endpoint.

Until now there is no decision from ECHA available regarding the implementation of the extended one generation reproductive toxicity study (EOGRTS, OECD 443) with Alkenes, C11-12, hydroformylation products, distn. residues.

Data source

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 443 (Extended One-Generation Reproductive Toxicity Study)
GLP compliance:
yes
Justification for study design:
TESTING PROPOSAL ON VERTEBRATE ANIMALS
1) Premating exposure duration: 10 weeks

The standard ten week premating exposure duration is proposed for this study.

2) Route of exposure and dose selection: oral, 1000 mg/kg bw/d

Route
We propose this study be done by the oral route even though this is not an expected route of exposure to this substance. The oral route is preferred because it is likely to increase the bioavailability of the test substance to test animals versus the dermal route.

The registrant also reserves the option of administering the test substance orally in the diet. For animal welfare reasons, oral gavage is not considered as it is prone to gavage errors that can lead to significant stress to the animals as a result of accidental aspiration. Dietary administration avoids this complication and also provides a toxicokinetic profile that is more comparable to that following dermal exposure (which is the most appropriate route of human exposure to the proposed test substance). The registrant proposes to possibility of conducting palatability studies as part of an investigation of the feasibility of the use of the dietary option. If the dietary option is not considered feasible, the registrant proposes the use of the gavage method of administration.

Dose selection
We also propose using, 1000 mg/kg bw/d, as the highest dose level for the study. The data summarized below suggest that there is no significant toxicity of the test substance is anticipated at doses up to 1000 mg/kg. A higher high dose level is not needed since humans are not expected to be exposed to the test substance at doses even approaching the proposed high dose. A dose range finding study will also be conducted to confirm the final dose selection for the study:

Additionally, an oral 90-day repeat dose study was conducted in rats on the registered substance. The study was designed to be compliant with OECD Guideline No. 408 and conducted in accordance with the OECD Principles of Good Laboratory Practice. The administration of the registered substance to rats once-daily by oral gavage for the 90 day period was well tolerated in rats at dose levels of 100, 300, or 1000 mg/kg/day. There were no mortalities that were considered to be attributable to the test item and no treatment-related macroscopic or microscopic abnormalities recorded. Based on these results, the no-observed-effect level (NOAEL) was considered to be 1000 mg/kg/day.

Also, a pre-natal developmental toxicity study was conducted with the registered substance administered to pregnant rats during the period of organogenesis. The study design was based on OECD Guideline of Testing of Chemicals No. 414 "Prenatal Developmental Toxicity Study", adopted 22nd January 2001. Dose levels administered were 0, 100, 300 and 1000 mg/kg/day. At levels up to 1000 mg/kg/day of the registered substance, there were no obvious effects of treatment on body weight gain, food consumption performance or clinical signs. The incidence of embryo-foetal deaths and mean fetal weights did not suggest any obvious effect of treatment. The type and distribution of fetal abnormalities and variants did not suggest any obvious effect of treatment.
Under the conditions of this study, the maternal and fetal, no observed effect levels (NOAEL), were both considered to be 1000 mg/kg/day.

Conclusively, the 1000 mg/kg bw/d dose is not expected to result in significant toxicity. However, since humans are not exposed to doses even close to this level, we believe this to be the appropriate high dose for this study. We also plan to confirm the appropriate nature of the 1000 mg/kg dose by conducting a dose range finding study prior to the main study. This study design should allow conclusion on classification and labelling, including categorisation, for the hazard endpoint for sexual function and for fertility according to CLP.

3) Extension of Cohort 1B and termination time for F2: extension not justified

According to, Appendix R.7.6-2 EOGRTS Study Design, pg. 501, the extension of cohort 1B to include the F2 generation shall be proposed by the registrant based on the following conditions being met (a and any of b(i), b(ii) or b(iii)) as shown below:

Basis for proposing an extension of cohort 1B to the F2 generation

Conditions

A. The substance has uses leading to significant exposure of consumers or professionals, taking into account, inter alia, consumer exposure from articles Yes – The substances have uses leading to significant exposure of consumers or professionals.

B (i). The substance displays genotoxic effects in somatic cell mutagenicity tests in vivo which could lead to classifying it as Mutagen Category 2, or No – The substances are not classified as Mutagen Category 1A or 1B or 2.

B (ii). There are indications that the internal dose for the substance and/or any of its metabolites will reach a steady state in the test animals only after an extended exposure, or No – The NOAEL of the 90-day subchronic study is not lower than the NOAEL observed in the developmental study on the registered substance. Additionally, the high dose achieved in the rather lengthy 90-day study suggests without any significant effects provides suggests that substance is not expected to shift steady state levels to a toxicologically significant degree.

B (iii) There are indications of one or more relevant modes of action related to endocrine disruption from available in vivo studies or non-animal approaches No - There are no indications based on the available study results that endocrine disruption is a relevant mode of action for the substances, additionally no structural alerts exist.

Therefore, based on the above considerations, the registrant does not believe that there is a basis for extending cohort 1B to include the F2 generation.

Additionally, the registrant is of the opinion that the extension of the cohort to F2 generation is unlikely to provide any meaningful results beyond those that will be obtained from the F1 generation in the proposed study. The rationale for the unlikelihood of obtaining meaning results in the F2 generation is discussed below.

Supporting arguments:
Piersma et al. investigated the necessity of producing a second generation to assess the potential for human health risks. The analysis included 498 rat multi-generation studies representing 438 different test substances. Detailed assessment of study reports revealed no critical differences in sensitivities between the generations on the basis of a consideration of all endpoints evaluated. This analysis indicated that the second generation mating and offspring will very rarely provide critical information (Piersma et al., 2011). Martinet al. (2009) conducted an analysis on 329 multi-generation studies on 316 chemicals using the ToxRefDB dataset of USEPA. This analysis supports the hypothesis that the second, F2 generation in these 329 studies would rarely impact either the qualitative or quantitative evaluations of these studies. Janer et al. (2007) evaluated 176 multi-generation studies to assess potential differences between the first and the second generation and came to the conclusion that the second generation in the two-generation studies considered affected neither the overall NOAEL nor the critical effect, and had no impact on the ensuing risk assessment, nor on classification and labeling. Therefore, if the second generation had not been included in the reproductive toxicity test, the ensuing risk assessment and classification and labeling would have basically been the same for the substances that were considered. Myers et al. (2008) detected by analysis of 22 two-generation studies, 3 substances with adverse effects on reproductive performance solely in the F1 generation (not F0), but in these three studies concomitant effects would have also been triggered the mating of the F1 generation. No effects were seen in the original parental (F0) generation which would have activated the change from a one- to a two-generation study. Beekhuijzen et al.(2009) reviewed nine two-generation studies in rats and recommended that further breeding should not be conducted when the effects on parental fertility and fecundity are clear after first pairing. However, mating of the F1 generation is warranted if the effects on parental reproduction/breeding parameters are ambiguous. Likewise, if development and/or viability of the F1 generation are adversely affected, a second mating deserves considerations as potential exists for compromised reproductive integrity of the F1 animals. Rorije et al. (2011) analyzed the possible impact on classification and labeling decisions of effects observed in second generation parental (P1) and offspring (F2) parameters in multi-generation studies. This was done for 50 substances classified as reproductive toxicants in Europe, for which a multi-generation study was available. The analysis shows that, except for a single case, effects observed in second generation mating and offspring did not impact the decision on classification and labeling for reproductive toxicity. Moreover, the single case where second generation mating and offspring effects appeared to be instrumental for classification would be identified as a reproductive toxicant in an extended one-generation reproductive toxicity study without second generation mating and offspring. Schultz et al. (2014) compared the responsiveness of the different generations and developmental stages in studies on reproductive toxicity. The F1 generation is identified as the most responsive generation in more than 50% of one-generation and multi-generation reproduction studies. Within the F1 generation the adult stage is mostly affected compared to the prenatal or postnatal stage. The findings in the F2 generation have shown a higher responsiveness than F1 only in 3% of the studies. Although in 29 studies new effects are observed in F2 offspring compared to F1 irrespective of dose levels, overall no severe new effects have emerged that would change classification and labeling and justify an F1 mating.


4) Inclusion of Cohorts 2A and 2B: not justified

The registrant does not believe there is a need to include cohorts 2A and 2B in the test design. This is based on:
• previous studies with the substance do not indicate neurotoxic effects such as changes in brain weight or in specific neural areas not secondary to body weight, changes in brain volume or specific neural areas or (histo)pathological findings in brain, spinal cord and/or nerves
• test animals exposure to the substance have not expressed any behavioural changes in the absence of general toxicity
• the substance is not known to have any mode of action associated with neurotoxicity such as cholinesterase inhibition and thyroid toxicity
• there are no indications that endocrine disruption is a relevant mode of action for the substance
• no structural analogues are known to show neurotoxic effects

5) Inclusion of Cohort 3: not justified

The registrant does not believe there is a need to include cohort 3 in the test design. This is based on:
• the substance has not caused biologically significant changes in haematology/clinical chemistry and/or organ weight associated with immunotoxicity such as reduced leucocyte count in combination with reduced spleen weight in repeated dose studies
• the substance has not caused significant effects to immunology organs such as thymus atrophy in repeated dose studies
• the substance is not classified as a (respiratory) sensitizer
• there are no indications that endocrine disruption is a relevant mode of action for the substance
• no structural analogues are known to show immunotoxic effects

Literature:
Beekhuijzen M, Zmarowski A, Emmen H, Frieling W. To mate or not to mate: a retrospective analysis of two-generation studies for evaluation of criteria to trigger additional mating in the extended one-generation design. Reprod Toxicol. 2009 Sep; 28(2):203-8.
Janer G, Hakkert BC, Slob W, Vermeire T, Piersma AH. A retrospective analysis of the two-generation study: what is the added value of the second generation? Reprod Toxicol. 2007 Jul; 24(1):97-102.
Janer G, Piersma, AH, Vermeire T, Slob W. A retrospective analysis of the added value of the rat two-generation reproductive toxicity study versus the rat subchronic toxicity study. Reproductive Toxicol. 2007; 24: 103-113.
Martin MT, Mendez E, Corum DG, Judson RS, Kavlock RJ, Rotroff DM, Dix DJ. Profiling the reproductive toxicity of chemicals from multigeneration studies in the toxicity reference database. Toxicol Sci. 2009 Jul; 110(1):181-90.
Myers DP, Willoughby CR, Bottomley Am, Buschmann J. An analysis of the results from Two-Generation Reproduction Toxicity Studies to assess the value of mating animals of the second (F1)generation for the detection of adverse treatment-related effects on reproductive performance. Reprod Toxicol. 2008 Sep; 26(1):47-50.
NTP Technical report on the toxicology and carcinogenesis studies of technical grade sodium xylenesulfonate (CAS No. 1300-72-7) in F344/N rats and B6C3F1 mice (dermal studies). NTP TR 464, NIH Publication No. 98-3880, NIH, USA, 1998.
Piersma AH, Rorije E, Beekhuijzen ME, Cooper R, Dix DJ, Heinrich-Hirsch B, Martin MT, Mendez E, Muller A, Paparella M, Ramsingh D, Reaves E, Ridgway P, Schenk E, Stachiw L, Ulbrich B, Hakkert BC. Combined retrospective analysis of 498 rat multi-generation reproductive toxicity studies: on the impact of parameters related to F1 mating and F2 offspring. Reprod Toxicol. 2011 May; 31(4):392-401.
Rorije E, Muller A, Beekhuijzen ME, Hass U, Heinrich-Hirsch B, Paparella M, Schenk E, Ulbrich B, Hakkert BC, Piersma AH. On the impact of second generation mating and offspring in multi-generation reproductive toxicity studies on classification and labelling of substances in Europe. Regul Toxicol Pharmacol. 2011 Nov; 61(2):251-60.
Schultz F, Batke M, Mangelsdorf I, Pohlenz-Michel C, Simetska N, Lewin G. Sensitivity of different generations and developmental stages in studies on reproductive toxicity. Toxicol. Lett. 2014 Feb; S0378-4274.
Til HP, Feron VJ, Huismans JW and de Groot AP, Subchronic toxicity study with Halvopon OR in albino rats, Central Inst for Nutrition and Food Research Report No: R2822, UK, 1969.


NON-CONFIDENTIAL NAME OF SUBSTANCE:
- Name of the substance on which testing is proposed to be carried out: Alcohols, C18-22, distn. residues / Alcohols, C18-22, distn. residues



Test material

Reference
Name:
Unnamed
Type:
Constituent

Test animals

Species:
rat
Sex:
male/female

Administration / exposure

Route of administration:
oral: unspecified

Results and discussion

Applicant's summary and conclusion