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Developmental toxicity / teratogenicity

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developmental toxicity
Type of information:
read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Justification for type of information:
No measured developmental toxicity/teratogenicity data are available for Cashew (Anacardium occidentale) Nutshell Extract, Decarboxylated (Technical Grade), but reliable test data are available for a source substance Cashew (Anacardium occidentale) Nutshell Extract, Decarboxylated, Distilled (Distilled grade). Information from a repeat dose and reproductive toxicity screening test (OECD TG422) using Distilled grade demonstrated no effects on developmental parameters up to a dose of 1000 mg/kg bw/day. The developmental parameters included postnatal growth in terms of changes in pup weight.
Additional test data on the effects of the three grades on developmental toxicity will be obtained from the Pre-natal developmental toxicity studies Test method: EU B.31/OECD TG414 via the oral route) for Distilled grade and Cashew (Anacardium occidentale) Nutshell Extract, Decarboxylated, Distillation Residue (Distillation Residue) grades.
Under Annex XI of the REACH Regulation “General rules for adaptation of the standard testing regime set out in Annexes VII to X”, in addition to the specific rules set out in Column 2 of Annexes VII to X, a registrant may adapt the standard testing regime in accordance with the general rules set out in Section 1 of the Annex. One approach that may be used is the grouping of substances and the read-across approach (Section 1.5 of Annex XI). An overall grouping and read-across rationale has been developed for the three grades of cashew nutshell extract. This has involved using data for two source substances Distilled and Distillation Residue grades to read-across the required data for Technical grade by interpolation. In this context interpolation is “the estimation of a value for a member of the group using measured values from other members on both sides of that member within the defined group spectrum”.
The justification for the read-across approach results from the commonality of the constituents and functional groups in the three grades and the common modes of action for specific localised endpoints that are manifest in physico-chemical, environmental fate and toxicological properties that are similar or follow a regular pattern as a result of structural similarity. Further details on the justification for using the interpolation based read-across approach are given in the accompanying document “Report on the development of an updated grouping and read-across rationale for the three grades of processed Cashew Nutshell extract”. The following points are relevant:
• The three grades are manufactured using a common process in which the unprocessed cashew nutshell extract is heated, which produces Technical grade. Subsequent distillation does not result in the formation of any new constituents in the resulting Distilled and Distillation Residue grades, but rather changes in the proportion of certain constituents relative to those present in Technical grade.

• In all the three grades the proportions of three out of the five key constituents namely the low boilers, C17 phenolics and high boilers (cardol and 2-methylcardol) are similar. Whilst the lightest, lower molecular weight non-polymeric constituents (such as cardanol) and the highest molecular weight polymeric constituents vary between the grades, Technical grade compositionally lies between Distilled and Distillation Residue grades.

• For all the physico-chemical parameters for which measured data are available (relative density, vapour pressure, water solubility, octanol-water partition coefficient, flash point and flammability) the values estimated for the target substance Technical grade from the results generated in tests on the source substances Distilled and Distillation Residue grade are consistent with the actual measured values for Technical grade. The consistency of the estimated and measured values for these endpoints for Technical grade indicate that the read-across approach is appropriate and that reliable results can be generated by interpolation from the source substances (Distilled and Distillation Residue grades). In particular, there is consistency for the key physico-chemical parameters which influence toxicological behaviour of the three grades of processed cashew nutshell extract, namely: water solubility, octanol-water partition coefficient (logKow) and vapour pressure.

• Based on mammalian toxicity studies conducted with the Distilled grade, the following points can be concluded regarding the substance. Systemic effects following repeated dosing indicate that Distilled grade is absorbed via the gastro-intestinal tract. The rate and extent of absorption cannot be elucidated from the data available. Only local effects were observed from an acute dermal toxicity study, and also a skin irritation and sensitisation studies. It is likely that the skin barrier will be compromised by the irritation/sensitisation observed following application of Distilled grade, and that some absorption via this route will occur. Systemic effects in the lung, mesenteric lymph nodes, stomach and duodenum were observed, indicating that Distilled grade is distributed throughout the body, however, the extent of such distribution is unknown. There is no data available regarding metabolism or excretion of the Distilled grade.
The conclusions discussed above suggest similar local and systemic toxicity profiles for all the three substances. The use of data from two source substances Distilled and Distillation Residue grades to read-across to Technical grade is considered to provide greater confidence in the predicted data for the target substance, as testing at the two ends of the compositional spectrum will reveal the toxicity or lack of toxicity of all the key constituents (including those of their degradation products) which are present in the Technical grade. On this basis Technical grade is considered likely to demonstrate responses with regard to reproductive parameters that are consistent with those observed for Distilled grade (no effects on developmental parameters up to a dose of 1000 mg/kg bw/day).

Category: Cashew Nutshell Extract category

Data source

Materials and methods

Test material


Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:
Maternal toxic effects:yes

Details on maternal toxic effects:
There were no toxicologically significant deaths during the study.

Increased salivation was detected prior to dosing and up to 5 hours after dosing for animals of either sex treated with 1000 mg/kg bw/day from Day 9 onwards. One female treated with 150 mg/kg bw/day developed clinical signs consistent with inappropriate dosing on Day 5 and was subsequently terminated. One female treated with 1000 mg/kg bw/day had given birth to a number of pups of which the majority were found dead. Several clinical signs were observed in this animal, and the animal and litter were terminated.

A slightly reduced bodyweight gain was observed for 1000 mg/kg bw/day males during the first two weeks of the study. Reduced bodyweight gain was also observed for 1000 mg/kg bw/day females during the later stages of the gestation period.

No adverse effect on dietary intake or food efficiency were detected.

No adverse effect on dietary intake or food efficiency were detected.

No intergroup differences were detected.


Haematological assessments revealed elevated platelet counts in animals of either sex treated with 1000 mg/kg bw/day. Elevated haemoglobin, erythrocyte and haematocrit was also evident for males treated at 1000 mg/kg bw/day. No such effects were detected at 150 and 15 mg/kg bw/day.

An increase in aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase levels were observed for 1000 mg/kg bw/day animals of either sex, together with elevated inorganic phosphorus, bilirubin and urea, and reduced cholesterol levels.


Open field arena observations revealed increased salivation for individual animals of either sex treated with 1000 mg/kg bw/day from Week 3.

Females treated with 1000 mg/kg bw/day showed elevated liver weights.


Groups of alveolar macrophages were seen with a higher incidence for females treated with 1000 mg/kg bw/day.
A higher incidence of sinus histiocytosis and/or foamy histiocytes was observed in relation to treatment with 1000 mg/kg bw/day.
Hyperkeratosis, frequently associated with acanthosis was seen in the forestomachs of animals of either sex treated with 1000 mg/kg bw/day. Focal ulceration of the forestomach epithelium was also seen in one high dose female.
Mucosal hypertrophy was seen in three males at the top dose group. A low incidence of mucosal hypertrophy was observed in females in all dose groups.

No adverse effects on mating or fertility were observed.

No effects detected.

No effects detected.

No effects detected.

No effects detected.

Effect levels (maternal animals)

open allclose all
Dose descriptor:
Effect level:
150 mg/kg bw/day (actual dose received)
Based on:
test mat.
Basis for effect level:
other: maternal toxicity
Dose descriptor:
Effect level:
1 000 mg/kg bw/day (actual dose received)
Based on:
test mat.
Basis for effect level:
other: developmental toxicity

Results (fetuses)

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

Details on embryotoxic / teratogenic effects:
No effects occurred.

Effect levels (fetuses)

Dose descriptor:
no treament related effects
Effect level:
1 000 mg/kg bw/day
Based on:
test mat.
Basis for effect level:
reduction in number of live offspring
changes in sex ratio
fetal/pup body weight changes
changes in litter size and weights
changes in postnatal survival
external malformations

Fetal abnormalities

not specified

Overall developmental toxicity

Developmental effects observed:
not specified

Applicant's summary and conclusion

A NOAEL of 150 mg/kg bw/day has been identified for systemic toxicity. A NOAEL of 1000 mg/kg bw/day has been identified for reproductive parameters.

Executive summary:

In a subchronic toxicity study Cashew Nutshell Extract, Decarboxylated, Distilled (Distilled Grade) as administered to 5 Sprague-Dawley rats/sex/dose via gavage at dose levels of 0, 15, 150, or 1000 mg/kg bw/day).


Systemic changes in the lungs, mesenteric lymph node, stomach and duodenum occurred at the highest dose.The NOAEL is 150 mg/kg bw/day.


This repeat dose/reproductive toxicity screening study in the rat is acceptable and satisfies the guideline requirement for a subchronic oral study OECD 422 in rats.