No IUPAC name is currently defined for Cashew (Anacardium occidentale) Nutshell Extract, Decarboxylated (Technical Grade).

Repeated dose toxicity: oral

Administrative data

Endpoint:

short-term repeated dose toxicity: oral

Remarks:

combined repeated dose and reproduction / developmental screening

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Justification for type of information:

1 HYPOTHESIS FOR THE CATEGORY APPROACH (ENDPOINT LEVEL) The basis for the adoption of a category approach for the three grades of processed Cashew Nutshell Extract is 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. The ECHA Final Decisions on the Annex IX and X (mammalian toxicology, ecotoxicology and environmental fate) Testing Proposals for three grades confirmed the applicability of a category approach which involves reading data across from the source substances Cashew Nutshell Extract, Decarboxylated, Distilled (Distilled Grade) and Cashew Nutshell Extract, Decarboxylated, Distillation Residue (Distillation Residue Grade) to the target substance Cashew Nutshell Extract, Decarboxylated (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”. Further details on the justification for using the interpolation based read-across approach are given in the attached document “Report on the grouping and read-across rationale for the three grades of processed Cashew Nutshell Extract”. The interpolation approach has been applied to the Annex IX OECD TG408 and TG414 testing on Distilled and Distillation Residue Grades. For the Annex VII and VIII endpoints a programme of testing has been carried out to provide comparative information for the three grades and develop a data matrix to support the category and read-across approaches. This has involved generating reliable data for all Annex VII and VIII physico-chemical and environmental fate endpoints and certain mammalian toxicity properties. However, based on the discussions surrounding the Final Decisions it was not considered necessary to apply this approach retrospectively to address all identified data gaps at Annexes VII and VIII. The original data used for the registration of a single substance (Cashew Nutshell Liquid, CAS Number 8007-24-7) was largely based on data for Distilled Grade since this was considered to be the most (eco) toxicologically active form, given the higher content of low molecular weight constituents (such as cardanol) and the low content of polymeric species. Therefore, based on the use of the category approach it is considered appropriate to read-across from the existing short-term mammalian toxicity data for Distilled Grade to the other two grades.
2. CATEGORY APPROACH JUSTIFICATION (ENDPOINT LEVEL) No measured repeated dose toxicity (oral exposure) 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 TG 422) using Distilled grade demonstrated effects on a number of parameters. 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. There were no toxicologically significant deaths during the study. Open field arena observations revealed increased salivation for individual animals of either sex treated with 1000 mg/kg bw/day from Week 3. On this basis Technical Grade is considered to demonstrate a similar response in a 28 day repeated dose study to those recorded for Distilled Grade.

Materials and methods

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

No IUPAC name is currently defined for Cashew (Anacardium occidentale) Nutshell Extract, Decarboxylated, Distilled (“Distilled Grade”).

EC Number:

700-991-6

Molecular formula:

Cardanol (saturated side chain): Formula: C21 H36 O Cardanol (monoene): Formula: C21 H34 O Cardanol (diene): Formula: C21 H32 O Cardanol (triene): Formula: C21 H30 O

IUPAC Name:

No IUPAC name is currently defined for Cashew (Anacardium occidentale) Nutshell Extract, Decarboxylated, Distilled (“Distilled Grade”).

Details on test material:

- Name of test material (as cited in study report): Cashew nutshell liquid (distilled grade)
- Physical state: liquid
- Lot/batch No.: AZ0192
- Storage condition of test material: room temperature in the dark
- Other: dark brown slightly viscous liquid

Administration / exposure

Frequency of treatment:

Daily.

Results and discussion

Results of examinations

Clinical signs:

effects observed, treatment-related

Mortality:

mortality observed, treatment-related

Body weight and weight changes:

effects observed, treatment-related

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

no effects observed

Water consumption and compound intake (if drinking water study):

no effects observed

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Clinical biochemistry findings:

effects observed, treatment-related

Urinalysis findings:

not examined

Behaviour (functional findings):

effects observed, treatment-related

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Histopathological findings: neoplastic:

no effects observed

Details on results:

CLINICAL SIGNS AND MORTALITY
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.

BODY WEIGHT AND WEIGHT GAIN
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.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
No adverse effect on dietary intake or food efficiency were detected.

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

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study)
No intergroup differences were detected.

OPHTHALMOSCOPIC EXAMINATION
N/A

HAEMATOLOGY
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.

CLINICAL CHEMISTRY
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.

URINALYSIS
N/A

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

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

GROSS PATHOLOGY
None

HISTOPATHOLOGY: NON-NEOPLASTIC
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.

OTHER FINDINGS
MATING
No adverse effects on mating or fertility were observed.

OFFSPRING LITTER SIZE AND VIABILITY
No effects detected.

OFFSPRING GROWTH AND DEVELOPMENT
No effects detected.

LITTER OBSERVATIONS
No effects detected.

UTERINE EXAMINATION
No effects detected.

Effect levels

1

Dose descriptor:

NOAEL

Effect level:

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

Sex:

male/female

Basis for effect level:

other: Based on systemic changes in the lungs, mesenteric lymph node, stomach and duodenum.

2

Dose descriptor:

NOAEL

Effect level:

1 000 mg/kg bw/day (actual dose received)

Sex:

male/female

Basis for effect level:

other: No treatment effects occurred on reproduction or offspring development.

Target system / organ toxicity

Critical effects observed:

not specified

Any other information on results incl. tables

A document which justifies the read–across from Cashew (Anacardium occidentale) Nutshell Extract, Decarboxylated, Distilled (“Distilled Grade”) and Cashew (Anacardium occidentale) Nutshell Extract, Decarboxylated, Distillation Residue (“Distillation Residue Grade”) to Cashew (Anacardium occidentale) Nutshell Extract, Decarboxylated (“Technical Grade”) is attached in the Category object.

Applicant's summary and conclusion

Conclusions:

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) was 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.