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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Description of key information

For Coniferan the repeated dose toxicity information is derived using information from the close analogue Verdox and with support of another analogue Cyclacet being tested in an OECD TG 408 study

Verdox tested in a study similar to OECD TG 408 (extended to 10 weeks OECD TG 422): No adverse effect observed, NOAEL ≥437 mg/kg bw for males and females.

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Study duration:
subacute
Species:
rat
Quality of whole database:
One OECD TG 422 with the closest analogue Verdox: one OECD TG 408 study with the analogue Cyclacet

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

In the section below the key results from the OECD TG 422 study of the analogue Verdox will be described first. Secondly a summary of the OECD TG 408 study of Cyclacet will be presented to support the no adverse effect conclusion. Finally the read across justification will be presented.


Summary of the similar to OECD TG 408 (extended to at least 10 weeks OECD TG 422) with Verdox


In the GLP compliant combined repeated dose and reproduction / developmental screening study, performed according to OECD guideline 422, Wistar rats were treated with the test substance (0, 75, 200, and 500 mg verdox/kg bw/day, nominal expected dose levels) in the diet,during a premating period of 10 weeks and during mating (1 week), gestation and lactation until postnatal day 4. The actual test substance intake ranged between 46-69 for males and 42-71 for the females of the low dose group. For the mid dose group the actual test substance concentration ranged from 141-209 for the males and 129-209 for the females. For the high dose group the actual test substance concentration ranged from 415-617 for the males and ranged between 381-672 for the females. Clinical observations during the premating, gestation and lactation period did not reveal any treatment-related changes in the animal’s appearance, general condition or behaviour. Neurobehavioural observations and motor activity assessment did not indicate any neurotoxic potential of the test substance. No toxicological relevant effects on body weight and food consumption were observed in both sexes. No treatment related effects were observed on pre-coital time, mating index, duration of gestation, pre- and postimplantation loss, number of corpora lutea, number of implantation sites and number of live pups on lactation. No treatment related clinical signs in pups, no effect on sex ratio in pups on day 1 and 4 of lactation, no effects on the mean pup body weight and body weight gain on lactation days 1 and 4 and no treatment-related macroscopic observations in pups that were stillborn or that died during lactation were observed. No effects on red blood cell variables or clotting potential was observed. A statistically significant increase in urea-concentration was observed in males of all dosing groups which might be related to the observed kidney effects (α2u-microglobulin nephropathy). No treatment-related effects were observed on sperm-parameters (epidydimal sperm motility, sperm count and morphology and testicular sperm count). An increased relative liver weight was observed in high dose males which was considered as an adaptive response to increased physiological demand. A dose related increase in relative kidney weight was observed in mid and high dose males which was related to the observed α2u-microglobulin nephropathy. No effects on organ weights were observed in females. Effects observed on kidney weights and urea-concentrations were considered to be related to α2u-microglobulin nephropathy which was confirmed by immunocytochemical staining of the α2u-microglobulin protein in the cortical tubular epithelial cells. This effect observed in rats is generally regarded as of no toxicological relevance for humans. Macrosopic and microscopic examination did not reveal any treatment-related effects. In conclusion, the NOAEL for Verdox for males and females in this study was ≥ 500 mg/kg body weight in the diet. Based on the absence of effects on fertility parameters and developmental parameters, the NOAEL for Verdox for fertility and developmental toxicity in this study was ≥ 500 mg/kg body weight in the diet. A NOAEL of 500 mg/kg body weight in the diet is equivalent to an overall intake of at least 505 mg/kg body weight/day for males and at least 437 mg/kg body weight/day for females.


Summary of the OECD TG 408 study with the analogue Cyclacet


For Cyclacet a sub-chronic repeated dose toxicity study was performed according to OECD 408 and under GLP conditions. In the study, rats were orally exposed to Cyclacet for 90 days via the food. The dose levels were 0, 200, 2000, 6000, and 20000 ppm, corresponding to 0, 15.3, 154.9, 464.1, and 1504.6 mg/kg bw/day, respectively. Clinical signs, functional observations, body weight change, dietary intake, and water consumption were monitored during the study. During week 7 and at the end of the study, haematology, blood chemistry and urinalysis were evaluated. Furthermore, oestrus cycle assessment was performed on female animals between week 6 and 7 and week 12 and 13.Opthalmoscopic examination was performed at the start and end of the study in control and high-dose animals. At the end of the study, all animals were subjected to gross necropsy examination and histopathological examination of tissues was performed on animals from control and high-dose. Furthermore, sperm assessment was performed on males at necropsy. Reduced overall body weight was observed in male and female animals in the highest dose group, correlated with reduced food consumption and adverse effects on food efficiency, indicating decreased food palatability. At the highest dose level, reduced chloride concentration, sodium concentration, aspartate aminotransferase levels, alanine aminotransferase levels, bile acid levels, and increased cholesterol levels were observed in male animals. The observed changes in aminotransferases, bile acid and cholesterol can be explained by the reduced food consumption. Changes in chloride and sodium concentrations may be explained by the observed kidney effects in males. Increased kidney weights were also observed in males, as well as hyalin droplet nephropathy, which is a rat-specific effect that is not relevant for humans. In females, no toxicologically significant effects were observed in clinical chemistry, organ weights or histopathology. Therefore the NOAEL could be established as the highest dose tested, >=20000 ppm or >=1500 mg/kg bw/day, under the conditions of this test.


 


Repeated dose toxicity of Coniferan (CAS #67874-72-0) using read across from substances Verdox (CAS #20298-69-5) and Cyclacet.


 


Introduction and hypothesis for the analogue approach


Coniferanisanacetate-ester attached to a cyclohexyl ring with a tert-pentyl-group attached at the ortho-position. For this substance no repeated dose toxicity data are available. In accordance with Article 13 of REACH, lacking information should be generated whenever possible by means other than vertebrate animal tests, i. e. applying alternative methods such as in vitro tests, QSARs, grouping and read-across. For assessing the repeated dose toxicity of Coniferan the analogue approach is selected because for a closely related analogue, Verdox, repeated dose-reproscreen information is available which can be used for read across. In addition, a similar analogue, Cyclacet, for which a 90-day study is available will be added to support the no adverse effects at the limit dose of ≥1000 mg/kg bw.


Hypothesis: Coniferan has no adverse effects in repeated dose toxicity because Verdox and Cyclacet have shown no adverse effects in ca. 90-days repeated dose toxicity studies. The one methyl group less in Verdox and the one additional C-atom in Cyclacetis not expected to influence the long term systemic effects.


Available information: The target chemical Verdox is tested in an extended almost 90-day OECD TG 422 study. The test is well conducted and in compliance with GLP guidelines and therefore receives a reliability of 1.


Target chemical and source chemical(s)


Chemical structures of the target chemical and the source chemicals are shown in the data matrix, including physico-chemical properties and toxicological information, thought relevant for repeated dose of both substances.


Purity / Impurities


Itis not expected that the impurities of the source chemical affect the read-across justification. Coniferan is a multi-constituent containing two stereo isomers. The purity of Coniferan is close to 100% therefore impurities will not affect the repeated dose results. In view of Verdox being a multi-constituent also containing two stereo isomers and having a purity close to 100%, there will be no significant impurities relevant for read across. Cyclacet is a reaction mass containing two isomers which differ in the position of the double bond in the pentyl ring. One constituent has a 5-yl position, the other a 6-yl position. This position is not anticipated to differ the systemic toxicity. Cyclacet has a purity close to 100%.


Analogue approach justification


According to Annex XI 1.5 read across can be used to replace testing when the similarity can be based on a common backbone and a common functional group.


Verdox was selected for read across because it was the most similar substance when compared to other cyclohexyl acetic esters such as presented in Belsito et al., 2008 (ECHA, 2017, RAAF).


Structural similarities and differences:Coniferan as well as the structural analogue Verdox have a cyclohexyl ring, a tert-butyl- group in ortho position and attached to the ring is an acetate ester as functional group. Coniferan has one additional methyl group attached to the tert-butyl group and is a tert-pentyl-groupThis difference between the target and source chemical is not expected to influence significantly the repeated dose toxicity potential of these two substances. Cyclacet has a bridged cyclohexyl ring to which a pentene ring is attached instead of a tert-pentyl group. These groups attached to the ester are both hydrophobic hydrocarbons. The 3-D position of the alkyl groups for both Coniferan and Verdox are not different. Cyclacet will have a more flat structure, which may somewhat influence the bioavailability but overall is not anticipated to result in differences in systemic toxicity.


Toxico-kinetic similarities and differences:Absorption:Coniferan and Verdox have similar molecular weight and physico-chemical properties indicating similar absorption characteristics (molecular weight (212.33 and 198.31g/mol,),log Kow (5.4 and 4.75), water solubility (7.6 and 10 mg/L, and vapour pressure (4.24 and 9.72 Pa at 25 °C), respectively). This indicates that Coniferan and Verdox will absorb similarly via the gastrointestinal tract. Cyclacet is slightly more stable resulting in lower vapour pressure, higher water solubility and lower log Kow. All these values are still very much in the same range and the substances are not expected to differ in bioavailability. The structure of Cyclacet being a bit more flat due to the attached pentene ring will present some enhanced bioavailability, because the diffusion through the cell membranes is smoother compared to Coniferan and Verdox.


Metabolism:Small chain straight alkyl esters such as Coniferan, Verdox and Cyclacet are likely to be metabolized by carboxylesterases in the gut, liver, lungs and skin as presented below (Belsito et al., 2008, Yamada et al., 2013) (see metabolism figures 1 and 2), resulting in a cyclic alcohol and acetic acid. Oxidation of methyl groups or at the ring can also occur (OECD Toolbox, data not shown) and conjugation is also anticipated to make the substances more hydrophilic and more easy to excrete. The acetic acid will be formed when all three substances metabolize and will therefore not influence the read across between the substances.


 


 


Fig. 1   The metabolic scheme of Coniferan, Verdox and Cyclacet from top to bottom, respectively. Acetic acid is the common metabolite, the other part of the substance turns into the respective alcohols.


Toxico-dynamic aspect: Reactivity: The ester is the functional group of all three substances. The acid part is the acetic acid is present in all three substances and will therefore not give differences in systemic toxicity. The alcohol part is very similar between Coniferan and Verdox. Liver weight increase is the effect seen for Verdox due to the metabolic needs. This effect is also seen in Cyclacet showing that Cyclacet liver metabolism is occurring at an increased level. Also alpha-hydrocarbon nephropathy is observed and confirmed in both Verdox and Cyclacet further confirming a similar toxico-dynamic profile. The OECD Toolbox (3.3.5) presents a similar toxicological profile (data not shown).


Similarities in results for toxicological endpoints between the target and the source chemical(s):The acute toxicity information show a low order of toxicity of Coniferan and Verdox as these are > 5000 mg/kg bw for rats. Cyclacet has a somewhat lower acute oral value of 2750 mg/kg bw, which may be due to the slightly higher bioavailability.


Uncertainty of the prediction:There is no remaining uncertainty, in view of similarities in structure, toxico-kinetic (absorption and metabolism) and anticipated toxico-dynamic profile (reactivity) the read across is justified.In accordance with ECHA Read-Across Assessment Framework (RAAF) (2017) the read across would receive a score of 5.


Data matrix


The relevant information on physico-chemical properties and toxicological characteristics are presented in the Data matrix.


Conclusions per endpoint for Hazard assessment and C&L.


For Verdox no adverse effects are derived at ≥437 mg/kg bw in an extended almost-90-days OECD 422. In addition, for Cyclacet no adverse effects were seen at ≥1500 mg/kg bw in a 90-day study according to OECD TG 408. Therefore for Coniferan no adverse systemic effects are anticipated in a 90-day repeated dose toxicity.


Final conclusion on hazard, C&L and risk characterisation


The NOAEL for Coniferan is ≥1500 mg/kg bw and no adverse effects observed. Based on these results the substance does not need to be classified for repeated dose toxicity according to CLP Regulation (EC) No. 1272/2008 and its updates.Based on these results the conclusion for the starting point of the risk characterization is that for this substances there are ‘no hazard is identified’ and that a DNEL is not derived.


 


Data matrix for the read across to Coniferan from Verdox and Cyclacet




































































































































Common names



Coniferan



Verdox



Cyclacet



Chemical structures



 



 



 



CAS no



67874-72-0



20298-69-5



-



EC no



Registration in 2018



243-718-1



911-369-0



Empirical formula



C13H24O2



C12H22O2



C12H16O2



Smiles



 



 



CC(=O)OC3CC1CC3C2CC=CC12



Physico-chemical data



 



 



 



Molecular weight



212.33



198.31



192



Physical state



Liquid



Liquid at 30°C



Liquid



Melting point, °C



-20



29.8



-20



Boiling point, °C



251.9



232



245



Vapour pressure, Pa



4.24 at 24°C



9.72 at 23°C



2.12 at 23°C



Water solubility, mg/L



7.6 at 24°C



10 at 23°C



186 at 23°C



Log Kow



5.4



4.75



3.9



Human health endpoints



 



 



 



Acute oral


LD50 in mg/kg bw



4388 (mouse)


> 5000 (rat)


(OECD TG 401)



 


4600 (rat)


(OECD TG 401)



 


2750 (rat)


(OECD TG 401)



Acute dermal LD50 in mg/kg bw



> 5000 (rat)


(OECD TG 402)



> 5000 (rat)


(OECD TG 402)



>5000 (rat)


(OECD TG 402)



Repeated dose


NOAEL in mg/kg bw



Read across from Verdox and Cyclacet



≥ 437 mg/kg bw/day


(almost 90-days extended OECD TG 422)



≥ 1500 mg/kg bw (OECD TG 408)



Reproductive toxicity



 



 



 



Fertility


NOAEL in mg/kg bw



Read across from Verdox



≥ 437 (almost 90-days extended OECD TG 422)



≥1500 mg/kg bw


(OECD TG 408)



Developmental toxicity (OECD TG 422)



Read across from Verdox



≥ 437


(almost 90-days extended OECD TG 422)



≥1000 mg/kg bw


(OECD TG 421)



 


References


Belsito et al., A toxicologic and dermatologic assessment of cyclic acetates when used as


fragrance ingredients, Food and Chemical Toxicology 46 (2008) S1–S27


 


Yamada et al., A category approach to predicting the repeated-dose hepatotoxicity of allyl esters, Regulatory Toxicology and Pharmacology 65 (2013) 189–195

Justification for classification or non-classification

The NOAEL of Coniferan is considered to be >= 437 mg/kg bw based on the analogue information of Verdox. No adverse effects are observed and therefore, classification is not warranted according to CLP (EC 1272/2008 and its amendments).