U.S. Environmental Protection Agency December, 2009 

Hazard Characterization Document 

tial hazards (toxicity) for humans or the 

nvironment. 

of 

statements regarding the possibility of unreasonable risk of 

jury to health or the environment. 

y on 

on, a 

 their being 

f high quality, highly relevant to hazard characterization, and publicly available. 

d 

ts are 

 

SCREENING-LEVEL HAZARD CHARACTERIZATION 

Cashew, Nutshell Liquid 

(CASRN 8007-24-7) 

The High Production Volume (HPV) Challenge Program1

 was conceived as a voluntary 

initiative aimed at developing and making publicly available screening-level health and 

environmental effects information on chemicals manufactured in or imported into the United 

States in quantities greater than one million pounds per year. In the Challenge Program, 

producers and importers of HPV chemicals voluntarily sponsored chemicals; sponsorship 

entailed the identification and initial assessment of the adequacy of existing toxicity 

data/information, conducting new testing if adequate data did not exist, and making both new 

and existing data and information available to the public. Each complete data submission 

contains data on 18 internationally agreed to “SIDS” (Screening Information Data Set1,2) 

endpoints that are screening-level indicators of poten

e

The Environmental Protection Agency’s Office of Pollution Prevention and Toxics (OPPT) is 

evaluating the data submitted in the HPV Challenge Program on approximately 1400 sponsored 

chemicals by developing hazard characterizations (HCs). These HCs consist of an evaluation 

the quality and completeness of the data set provided in the Challenge Program submissions. 

They are not intended to be definitive 

in

The evaluation is performed according to established EPA guidance2,3 and is based primaril

hazard data provided by sponsors; however, in preparing the hazard characterization, EPA 

considered its own comments and public comments on the original submission as well as the 

sponsor’s responses to comments and revisions made to the submission. In order to determine

whether any new hazard information was developed since the time of the HPV submissi

search of the following databases was made from one year prior to the date of the HPV 

Challenge submission to the present: (ChemID to locate available data sources including 

Medline/PubMed, Toxline, HSDB, IRIS, NTP, ATSDR, IARC, EXTOXNET, EPA SRS, etc.),

STN/CAS online databases (Registry file for locators, ChemAbs for toxicology data, RTECS, 

Merck, etc.) and Science Direct. OPPT’s focus on these specific sources is based on

o

OPPT does not develop HCs for those HPV chemicals which have already been assessed 

internationally through the HPV program of the Organization for Economic Cooperation an

Development (OECD) and for which Screening Initial Data Set (SIDS) Initial Assessment 

Reports (SIAR) and SIDS Initial Assessment Profiles (SIAP) are available. These documen

presented in an international forum that involves review and endorsement by governmental 

1

 U.S. EPA. High Production Volume (HPV) Challenge Program; http://www.epa.gov/chemrtk/index.htm. 2

 U.S. EPA. HPV Challenge Program – Information Sources; http://www.epa.gov/chemrtk/pubs/general/guidocs.htm. 3

 U.S. EPA. Risk Assessment Guidelines; http://cfpub.epa.gov/ncea/raf/rafguid.cfm. 

1
U.S. Environmental Protection Agency December, 2009 

Hazard Characterization Document 

uthorities around the world. OPPT is an active participant in these meetings and accepts these 

ublic. However, they do provide a vehicle for public access to a concise assessment of 

the raw technical data on HPV chemicals and information previously not readily available to the 

public. 

a

documents as reliable screening-level hazard assessments. 

These hazard characterizations are technical documents intended to inform subsequent decisions 

and actions by OPPT. Accordingly, the documents are not written with the goal of informing the 

general p

2
U.S. Environmental Protection Agency December, 2009 

Hazard Characterization Document 

Chemical Abstract Service 

Registry Number 

(CASRN) 

8007-24-7 

Chemical Abstract Service 

Name 

Cashew, nutshell liquid

Structural Formula Mixture of anacardic acid, cardanol, and cardol (see Section 1)

Summary 

This chemical is a liquid with low water solubility and low vapor pressure. It is expected to have 

low mobility in soil. Volatilization of cashew nutshell liquid is considered low to moderate. The 

rate of hydrolysis is considered negligible. The rate of atmospheric photooxidation is considered 

rapid. It is expected to have low persistence (P1) and low bioaccumulation potential (B1). 

The acute hazard to fish, aquatic invertebrates, and aquatic plants is based on estimated toxicity 

values for cardanol of 0.001 mg/L, 0.004 mg/L, and 0.010 mg/L, respectively. 

Acute oral toxicity of this chemical in rats is low. It is a dermal sensitizer in guinea pigs. An 

oral combined repeated-dose/reproductive/developmental screening study in rats showed 

histopathological effects on the lung and lymph nodes, and hematological effects in adult 

animals at a dose of 1000 mg/kg-day; the NOAEL for systemic toxicity was 150 mg/kg-day. In 

the same study, there was reproductive toxicity at 1000 mg/kg-day as demonstrated by an 

increase in dyctocia; the NOAEL for reproductive toxicity was 150 mg/kg-day. There was no 

evidence of developmental toxicity in this study and the NOAEL was 1000 mg/kg-day. This 

chemical did not induce gene mutations or chromosomal aberrations when tested in vitro. 

The acute toxicity for aquatic organisms is considered a data gap under the HPV Challenge 

Program. 

3
U.S. Environmental Protection Agency December, 2009 

Hazard Characterization Document 

The sponsor, Cardolite Corporation, submitted a Test Plan and Robust Summaries to EPA for 

Cashew Nutshell Liquid (CAS No. 8007-24-7; 9th CI Name: Cashew Nutshell Liq.) on June 5, 

2002. EPA posted the submission on the ChemRTK HPV Challenge website on June 5, 2002 

(http://www.epa.gov/chemrtk/pubs/summaries/casntliq/c13793tc.htm). EPA comments on the 

original submission were posted to the website on November 12, 2002. Public comments were 

also received and posted to the website. The sponsor submitted updated/revised documents on 

December 20, 2002, November 2, 2006 and April 6, 2007, which were posted to the ChemRTK 

website on January 21, 2003, November 16, 2006 and July 24, 2007, respectively. 

1 Chemical Identity

1.1 Identification and Purity

The following description is taken from the final Test Plan (2006): 

Cashew nutshell liquid is obtained from the shell of a cashew nut and is a source of naturally 

occurring phenols. About 30-35% of this chemical is present in the shell, which amounts to 

approximately 67% of the nut. Cashew nutshell liquid is traditionally obtained as a by-product 

during the process of removing the cashew kernel from the nut. 

Natural (i.e. cold, solvent extracted) cashew nutshell liquid is a liquid that contains 

approximately 70% anacardic acid, 18% cardol, and 5% cardanol (Fig 1), with the remainder 

being made up of other phenols and less polar substances. Anacardic acid, cardanol and cardol 

consist of mixtures of components having various degrees of unsaturation in the alkyl side-chain. 

Figure 1: Structures of Anacardic acid, Cardanol and Cardol 

4
U.S. Environmental Protection Agency December, 2009 

Hazard Characterization Document 

In technical (i.e. heat extracted) cashew nutshell liquid, the heating process leads to 

decarboxylation of the anacardic acid to form cardanol. Typically, the composition of technical 

cashew nutshell liquid is approximately 52% cardanol, 10% cardol, 30% polymeric material, 

with the remainder being made up of other substances. The technical cashew nutshell liquid is 

often further processed by distillation at reduced pressure to remove the polymeric material. The 

composition of distilled technical cashew nutshell liquid (Cardolite NC 511) is approximately 

78% cardanol, 8% cardol, 2% polymeric material, < 1% 2-methyl cardanol, 2.3% heptadecyl 

homologue triene, 3.8% heptadecyl homologue diene and the remainder other homologous 

phenols. 

1.2 Physical-Chemical Properties

The physical-chemical properties of cashew nutshell liquid are summarized in Table 1. Cashew 

nutshell liquid is a liquid with low water solubility and low vapor pressure. 

Table 1. Physical-Chemical Properties of Cashew Nutshell Liquid1

Property Value

CASRN 8007-24-7 

Molecular Weight 298-320 

Physical State Liquid 

Melting Point Liquid at room temperature 

Boiling Point Polymerizes and decomposes prior to boiling3

Vapor Pressure 3.8×10-7 mm Hg at 25°C (measured) 

Water Solubility 0.305 mg/L at 20°C (measured) 

Dissociation Constant (pKa) ~10.06 (estimated)2

Henry’s Law Constant 2.6×10-10–9.7×10-5 atm-m3/mole (estimated)

Log Kow >6.2 (measured) 

1

Cardolite Corporation, Inc. November 2, 2006. Revised Robust Summary and Test Plan for Cashew Nutshell 

Liquid. http://www.epa.gov/chemrtk/pubs/summaries/casntliq/c13793tc.htm. 2

SPARC. 2008. Online pKa and Property Calculator v. 4.2.1405-s4.2.1408. Accessed September 7, 2008. 

http://ibmlc2.chem.uga.edu/sparc/index.cfm?CFID=32727&CFTOKEN=65477992. 3 BP 225 °C @ 10 mm Hg US Patent 2,098,824

5
U.S. Environmental Protection Agency December, 2009 

Hazard Characterization Document 

2 General Information on Exposure

2.1 Production Volume and Use Pattern

Cashew, nutshell liquid had an aggregated production and/or import volume in the United States 

of 50 to 100 million pounds during calendar year 2005. 

Non-confidential information in the IUR indicated that the industrial processing and uses of the 

chemical include intermediates in the manufacture of other basic organic chemicals. Nonconfidential information in the IUR indicated that the commercial and consumer products 

containing the chemical include automotive care products. The HPV submission states that the 

chemical is primarily used in antioxidants, plasticizers and processing aids for rubber compounds 

and modifiers for plastic materials. Cashew nutshell liquid resins have been used extensively in 

the manufacture of friction-resistant components in applications such as brake and clutch linings. 

2.2 Environmental Exposure and Fate

No quantitative information is available on releases of this chemical to the environment. 

The environmental fate properties are provided in Table 2. Cashew nutshell liquid is expected to 

have low mobility in soil. Cashew nutshell liquid was shown to be readily biodegradable using a 

modified Sturm test (OECD 302D). The rate of volatilization of cashew nutshell liquid from 

water and moist soil is considered low to moderate. The rate of hydrolysis is considered 

negligible under environmental conditions. Cashew nutshell liquid is expected to have low 

persistence (P1) and low bioaccumulation potential (B1). 

Table 2. Environmental Fate Characteristics of Cashew Nutshell Liquid1

Property Value

Photodegradation Half-life 0.351–1.254 hours (estimated)

Hydrolysis Half-life Stable

Biodegradation 96% after 28 days (readily biodegradable) 

Bioconcentration BCF = 4.5 (estimated)

Log Koc 7.5–8.6 (estimated) 

Fugacity 

(Level III Model; simultaneous 

1,000 kg/hour emission to air, 

water, and soil compartments) 

Air = 0% 

Water = 1.86% 

Soil = 30.9 % 

Sediment = 67.2% 

Persistence2 P1 (low) 

Bioaccumulation2 B1 (low) 

1

Cardolite Corporation, Inc. November 2, 2006. Revised Robust Summary and Test Plan for Cashew Nutshell 

Liquid. http://www.epa.gov/chemrtk/pubs/summaries/casntliq/c13793tc.htm. 2

Federal Register. 1999. Category for Persistent, Bioaccumulative, and Toxic New Chemical Substances. 

Federal Register 64, Number 213 (November 4, 1999) pp. 60194–60204.

6
U.S. Environmental Protection Agency December, 2009 

Hazard Characterization Document 

3 Human Health Hazard

Acute Oral Toxicity 

Acute toxicity data conducted according to established guidelines were not submitted. However, 

during a range-finding study for the combined toxicity study (see below), Sprague-Dawley rats 

(3/sex/dose) were orally dosed with 0 or 1,000 mg/kg-bw/day for 14 days. No mortality 

occurred during the 14 day observation period. No clinically observable signs of toxicity were 

observed. No macroscopic abnormalities were observed at necropsy. 

LD50 > 1000 mg/kg-bw (14 daily exposures-only one dose tested) 

Repeated-Dose Toxicity 

In a combined repeated-dose/reproductive/developmental toxicity screening test, groups of 

Sprague-Dawley rats (10 sex/dose) were dosed via gavage daily at 0, 15, 150, or 1000 mg/kgbw/day for up to 49 days. Increased salivation was noted in animals of both sexes at the highdose level after day 9. Two high-dose females had deaths attributed to dystocia, slow or difficult 

labor; one was euthanized on day 21 and another found dead on day 22. High-dose females had 

statistically significant increased relative liver weights. High-dose males had statistically 

significant decrease in absolute brain weights. Hematological changes (elevated platelet, 

hemoglobin, erythrocyte, and hematocrit counts, elevated mean cell volume, and decreased mean 

cell hemoglobin concentration) were noted in high-dose males. An increase in mean cell volume 

was also noted in high-dose females. Clinical biochemistry changes (elevated aspartate and 

alanine aminotransferases, alkaline phosphatase, and inorganic phosphorus, reduction in 

cholesterol and elevated bilirubin) were noted in males and females at the high dose. High-dose 

males also had increased plasma urea, reduced glucose levels, and elevated albumin/globulin 

ratios. The significance and magnitude of changes are not noted. Histopathological changes at 

the high dose included higher incidence of alveolar macrophages in the lungs in females, 

abnormal multiplication of macrophages and/or foamy macrophages in the lymph nodes and 

overgrowth of the lining of the forestomach in both sexes, and thickening of the lining of the 

small intestine in males. 

LOAEL = 1000 mg/kg-bw/day (based on effects to the lungs, lymph nodes, and hematology) 

NOAEL = 150 mg/kg-bw/day 

Reproductive/Developmental Toxicity 

In the combined repeated-dose/reproductive/developmental toxicity screening test described 

previously, no adverse effects were reported on mating performance, fertility, precoital interval, 

duration of gestation, gestation index, number of implantations, or number of corpora lutea. In 

the high-dose dams, 2/10 had deaths attributed to dystocia, slow or difficult labor, on day 21 and 

22. An additional dam in this group died for unexplained reasons (assume gavage error) at a 

time not specified. No treatment related changes were noted in litter size, weight, sex ratio, 

viability index, post-natal growth rate or toxicologically significant effects on offspring. 

LOAEL (reproductive toxicity) = 1000 mg/kg-bw/day (based on deaths due to slow/difficult 

labor) 

NOAEL (reproductive toxicity) = 150 mg/kg-bw/day 

7
U.S. Environmental Protection Agency December, 2009 

Hazard Characterization Document 

NOAEL (developmental toxicity) = 1000 mg/kg-bw/day (based on no effects at the highest 

dose tested) 

 

Genetic Toxicity – Gene Mutation 

In vitro

(1) In bacterial reversion assays, Salmonella typhimurium strains (TA98, TA100, TA1535, 

TA1537 and TA1538) were exposed to cashew nutshell liquid at concentrations of 50, 150, 500, 

1500 or 5000 μg/plate in the presence and absence of metabolic activation. Three replicates 

were conducted per experiment. No cytotoxicity was noted at the maximum concentration of 

5000 μg/plate. A precipitate was observed at 1500 and 5000 μg/plate but it did not impact the 

scoring of colonies. No significant increase in the frequency of revertant colonies was recorded 

for any of the bacterial strains at any concentration, either with or without metabolic activation. 

Positive and solvent controls were tested and responded appropriately. 

Cashew nutshell liquid was not mutagenic in this assay.

(2) In forward mutation assays, Chinese hamster ovary (CHO-KI BH4) cells were exposed to 

cashew nutshell liquid, in two experiments, in the presence and absence of metabolic activation. 

In experiment 1 the concentrations ranged from 0.75 – 18 μg/mL and in the second experiment, 

the concentration range was and 0.75 – 24 μg/mL. Two replicates were conducted per 

experiment. Positive and solvent controls were tested and responded appropriately. The 

cytotoxic concentration with and without metabolic activation was 47.19 μg/mL (in the text, 

though the tables stated 24 μg/mL was toxic with activation). The test substance did not induce 

significant or dose-related mutant frequency in the presence or absence of metabolic activation in 

either of the two experiments. 

Cashew nutshell liquid was not mutagenic in this assay. 

Genetic Toxicity – Chromosomal Aberrations 

In vitro

In a chromosomal aberration test, human lymphocytes were exposed to cashew nutshell liquid in 

the presence and absence of metabolic activation in three experiments. The concentration ranges 

were 3 – 25 μg/mL, 0.78 – 37.5 μg/mL and 3.125 or 25 μg/mL in the first, second and third 

experiments, respectively. Harvest time for the cells was 20 hours for experiments 1 and 2, and 

44 hours for experiment 3. Two replicates were conducted for each experiment. Positive and 

solvent controls were tested which responded appropriately. The cytotoxic concentrations were 

12.5 μg/mL with metabolic activation and > 25 μg/mL without metabolic activation. The test 

substance did not induce a significant increase in the frequency of cells with chromosome 

aberrations or polyploid cells in either the presence or absence of metabolic activation. 

Cashew nutshell liquid did not induce chromosomal aberrations in this assay. 

8
U.S. Environmental Protection Agency December, 2009 

Hazard Characterization Document 

Additional Information 

Skin Sensitization 

In an assay using albino Dunkin Hartley guinea pigs (20 females/dose), intra-dermal induction 

was conducted using 1% (w/v) in liquid paraffin and 1% (w/v) in a mixture of Freund’s complete 

adjuvant plus distilled water. Topical induction was conducted using 25% (v/v) in liquid 

paraffin. Topical challenge was conducted with 5% or 2% (v/v) in liquid paraffin. Following 

intra-dermal induction, well defined, moderate to severe erythema was seen at 24- and 48-hour 

observations periods. Skin reactions observed at 24 and 48 hours after 5% topical challenge dose 

included very slight to well-defined erythema and very slight edema and desquamation. Very 

slight erythema in one animal and desquamation in three animals was present at 72 hours at the 

2% challenge dose. All animals showed an expected gain in body weight over the study period. 

The test substance produced a 70% (14/20) sensitization rate in the study and was classified as a 

“strong” sensitizer. 

Cashew nutshell liquid was sensitizing in this assay

Conclusion: Acute oral toxicity of this chemical in rats is low. It is a dermal sensitizer in 

guinea pigs. An oral combined repeated-dose/reproductive/developmental screening study in 

rats showed histopathological effects on the lung and lymph nodes, and hematological effects in 

adult animals at a dose of 1000 mg/kg-day; the NOAEL for systemic toxicity was 150 mg/kgday. In the same study, there was reproductive toxicity at 1000 mg/kg-day as demonstrated by 

an increase in dyctocia; the NOAEL for reproductive toxicity was 150 mg/kg-day. There was no 

evidence of developmental toxicity in this study and the NOAEL was 1000 mg/kg-day. This 

chemical did not induce gene mutations or chromosomal aberrations when tested in vitro. 

4 Hazards to the Environment

The sponsor did not submit measured aquatic toxicity data for cashew nutshell liquid, but 

provided data for log Kow and water solubility. ECOSAR (v. 1.00a) was used to assess acute 

aquatic toxicity of cardanol (CASRN 37330-39-5), the primary component of the sponsored 

distilled technical grade cashew nutshell liquid, which is a mixture of primarily cardanol (78%) 

and cardol (8%; CASRN 57486-25-6). 

Acute Toxicity to Fish 

A 96-hour LC50 value for fish exposed to cashew nutshell liquid was estimated by ECOSAR v. 

1.00a. 

96-h LC50 = 0.001 mg/L (estimated)

Acute Toxicity to Aquatic Invertebrates

A 48-hour EC50 value for Daphnia exposed to cashew nutshell liquid was estimated by ECOSAR 

v. 1.00a. 

48-h EC50 = 0.004 mg/L (estimated) 

9
U.S. Environmental Protection Agency December, 2009 

Hazard Characterization Document 

Toxicity to Aquatic Plants 

A 96-hour LC50 value for algae exposed to cashew nutshell liquid was estimated by ECOSAR v. 

1.00a. 

96-h LC50 = 0.010 mg/L (estimated) 

Conclusion: The acute hazard to fish, aquatic invertebrates, and aquatic plants is based on 

estimated toxicity values for cardanol of 0.001 mg/L, 0.004 mg/L, and 0.010 mg/L, respectively.. 

10
U.S. Environmental Protection Agency December, 2009 

Hazard Characterization Document 

Table 3. Summary Table of the Screening Information Data Set 

as Submitted under the U.S. HPV Challenge Program 

Endpoints SPONSORED CHEMICAL 

Cashew Nutshell Liquid (CASRN 8007-24-7) 

Summary of Environmental Effects – Aquatic Toxicity Data 

Fish 

96-h LC50 (mg/L) 0.001 (estimated) 

Aquatic Invertebrates 

48-h EC50 (mg/L) 0.004 (estimated) 

Aquatic Plants 

72-h EC50 (mg/L) 0.010 (estimated) 

Summary of Human Health Data

Acute Oral Toxicity 

LD50 (mg/kg-bw) >1000 

Repeated-Dose Toxicity 

NOAEL/LOAEL (mg/kg-bw/day) NOAEL = 150 

LOAEL = 1000 

Reproductive/Developmental Toxicity

NOAEL/LOAEL (mg/kg-bw/day) 

Reproductive Toxicity

Developmental Toxicity

NOAEL = 150 

LOAEL = 1000 

NOAEL = 1000 

Genetic Toxicity – Gene Mutation 

In vitro Negative 

Genetic Toxicity – Chromosomal 

Aberrations 

In vitro

Negative 

Additional Information – 

Skin Sensitization Positive 

 

11