Ricinoleic Acid

Ricinoleic acid (RA) like many of the ingredients in machine cutting fluids and other industrial formulations are potential dermal irritants, yet very little is known about its permeability in skin. 3H-ricinoleic acid mixtures were formulated with three commonly used cutting fluid additives; namely, triazine (TRI), linear alkylbenzene sulfonate (LAS), and triethanolamine (TEA) and topically applied to inert silastic membranes and porcine skin in vitro as aqueous mineral oil (MO) or polyethylene glycol (PEG) mixtures. These additives significantly decreased ricinoleic acid partitioning from the formulation into the stratum corneum (SC) in PEG-based mixtures. Except for LAS, all other additives produced a more basic formulation (pH = 9.3-10.3). In silastic membranes and porcine skin, individual additives or combination of additives significantly reduced ricinoleic permeability. This trend in ricinoleic acid disposition in both membranes suggests that the mixture interaction is more physicochemical in nature and probably not related to the chemical-induced changes in the biological membrane as may be assumed with topical exposures to potentially irritant formulations.

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 900(SRC), determined from a structure estimation method(2), indicates that ricinoleic acid is expected to have low mobility in soil(SRC). The estimated pKa of ricinoleic acid is 4.74(3), indicating that this compound will almost entirely exist in anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts(4). Volatilization from moist soil is not expected because the acid exists as an anion and anions do not volatilize(SRC). Ricinoleic acid is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 4.49X10-3 mm Hg at 25 °C(SRC), determined from a fragment constant method(5). Ricinoleic acid degraded 29.7% of theoretical oxygen demand after 24 hours using activated sludge(6), suggesting that biodegradation is an important environmental fate process(SRC).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 900(SRC), determined from a structure estimation method(2), indicates that ricinoleic acid is expected to adsorb to suspended solids and sediment(SRC). An estimated pKa of 4.74(3) indicates ricinoleic acid will exist almost entirely in the anion form at pH values of 5 to 9 and therefore volatilization from water surfaces is not expected to be an important fate process(SRC). According to a classification scheme(4), an estimated BCF of 56(SRC), from an estimated log Kow of 6.19(5) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is moderate(SRC). Ricinoleic acid degraded 29.7% of theoretical oxygen demand after 24 hours using activated sludge(6), suggesting that biodegradation is an important environmental fate process(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), ricinoleic acid, which has an estimated vapor pressure of 4.49X10-3 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase ricinoleic acid is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 4.6 hours(SRC), calculated from its rate constant of 8.45X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). The rate constant for the vapor-phase reaction of ricinoleic acid with ozone has been estimated as 1.3X10-16 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). This corresponds to an atmospheric half-life of about 2.1 hours at an atmospheric concentration of 7X10+11 ozone molecules per cu cm(4).

Using a structure estimation method based on molecular connectivity indices(1), the Koc of ricinoleic acid can be estimated to be 900(SRC). According to a classification scheme(2), this estimated Koc value suggests that ricinoleic acid is expected to have low mobility in soil. The estimated pKa of ricinoleic acid is 4.74(3), indicating that this compound will almost entirely exist in anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts(4).

Ricinoleic acid is found primarily in oils from the seeds of Ricinus communis (Euphorbiaceae). The compound accounts for about 90% of the triglyceride fatty acids of castor oil, and up to about 40% of the glyceride fatty acids of ergot oil(1). It is also found in the seeds of Argemone mexicana (Papaveraceae) at concentrations from 20,000-39,300 ppm; in seeds of Pterocarpus marsupium (Fabaceae); and in Zea mays (Poaceae)(2).

/HUMAN EXPOSURE STUDIES/ 202 consecutive patients (182 females, 20 males) with eczematous cheilitis who attended a contact and occupational dermatoses clinic in Singapore between January of 1996 and December of 1999 were patch-tested. Mean ages for female and male patients were 31.1 and 28.8 years, respectively. Patch tests were conducted according to International Contact Dermatitis Research Group (ICDRG) recommendations. Twenty-nine patients (2 males, 27 females) had positive reactions to ricinoleic acid. Of the 29 reactions, 22 were considered relevant positives.

/HUMAN EXPOSURE STUDIES/ Perfusion studies...in healthy volunteers.../showed/ ricinoleic acid provoked a marked secretion of fluid & concomitantly inhibited absorption of all solutes tested, incl glucose, xylose, l-leucine, l-lysine, folic acid, & 2-monoolein. Mechanism may be related to mucosal damage & altered mucosal permeability.

/SIGNS AND SYMPTOMS/ Castor oil is known for its purgative effects and can be used to induce labor. Both castor oil and ricinoleic acid are approved for use in food. The mechanistic basis for purgative actions likely includes the membrane-disruptive effects of detergent-like molecules, such as sodium ricinoleate (a "soap"). These effects have been shown to be dose-related and to exhibit a threshold below which no laxative response was evident, in both animals and in humans.

/SIGNS AND SYMPTOMS/ The lowest dose at which mortality occurred following an accidental ingestion was 5000 mg/kg.

For more Human Toxicity Excerpts (Complete) data for Ricinoleic acid (7 total), please visit the HSDB record page.

AEROBIC: Using activated sludge in wastewater treatment, the theoretical oxygen demand (the concentration of oxygen required to oxidize 500 mg/L of substrate completely) after 6, 12 and 24 hours was 5.5%, 17.6% and 29.7%, respectively, for ricinoleic acid(1). Ricinoleic acid was readily oxidized by activated sludge from three municipal waste treatment plants in Columbus, OH; in Warburg flasks with a ricinoleic acid concentration of 500 mg/L at 20 °C, the oxygen uptake was approximately 300 mg/L after 24 hours(2). These data suggest biodegradation may be an important environmental fate process(SRC).

An estimated BCF of 56 was calculated in fish for ricinoleic acid(SRC), using an estimated log Kow of 6.19(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is moderate(SRC).

An estimated pKa of 4.74(1) indicates ricinoleic acid will exist almost entirely in the anion form at pH values of 5 to 9 and therefore volatilization from water surfaces is not expected to be an important fate process(SRC). Volatilization from moist soil is not expected because the acid exists as an anion and anions do not volatilize(SRC). Ricinoleic acid is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 4.49X10-3 mm Hg(SRC), determined from a fragment constant method(2).

/LABORATORY ANIMALS: Acute Exposure/ A single dose of ricinoleic acid, the active component of castor oil, administered intragastrically to specific pathogen-free mice produced significant alterations in the proximal small intestinal mucosa. Two hours after drug administration, the duodenal villi were markedly shortened with massive exfoliation of columnar and goblet cells. This disruption of the mucosal barrier resulted in continuity between the intestinal lumen and the lamina propria of the villi. Because of the loss of the mucosal barrier, bacteria of the indigenous gastrointestinal flora translocated from the gastrointestinal lumen to the mesenteric lymph nodes, spleen, and liver...

/LABORATORY ANIMALS: Acute Exposure/ The primary autoxidation products of polyunsaturated fatty acids are known to stimulate DNA synthesis and induce ornithine decarboxylase activity in colonic mucosa. ... The present study ... determined the structural features of the oxidized fatty acids necessary for the stimulation of these two components of mitogenesis. Compounds were instilled intrarectally in either aqueous or mineral oil vehicles and 3 hr later (ornithine decarboxylase activity) or 12 hr later (tritiated thymidine incorporation), the animals were killed and the colonic mucosa harvested for measurement of the two parameters of cell proliferation. Hydroperoxy and hydroxy fatty acids derived from oleate and stearate were studied. Ricinoleic acid and the alpha,beta-unsaturated ketone derived from oleic acid were also investigated. The minimal requirement for stimulation of cell proliferation is the presence of an oxidized functionally adjacent to a carbon-carbon double bond. All active compounds studied were roughly equipotent, which suggests a common mediator may be involved. These results imply that, in addition to biliary steroids, the autoxidation products of unsaturated fatty acids may play a role in the enhancement of tumorigenesis by high levels of dietary fat. Furthermore, the data suggest a possible mechanism of action for the active compounds.

/LABORATORY ANIMALS: Acute Exposure/ A single 0.1 mL dose of ricinoleic acid (100 mg/mL) was administered intragastrically to fasted, specific pathogen-free mice (strain CD-1, number not stated). This dosage of Ricinoleic acid was determined, on a weight basis, to be approximately the dosage that is used therapeutically in humans. Groups of mice were killed at various intervals, and light microscopy and transmission and scanning electron microscopy were used to identify structural alterations. At 2 hr post dosing, the duodenal villi were markedly shortened when compared to control duodenal villi. This erosion of the villi throughout the duodenum caused massive exfoliation of columnar and goblet cells, filling the lumen with cellular debris and mucus. Disruption of the mucosal barrier resulted in continuity between the intestinal lumen and lamina priopria of the villi, with the loss of formed blood elements and lamina propria constituents into the intestinal lumen. The mucosal damage was much more localized at 4 hr post dosing, and the erosion of the villi had been largely repaired. Repair was complete at 6 hr post dosing.

CIR ingredient: Ricinoleic Acid

Present in the seeds of Ricinus spp, Euphorbiaceae and in the fatty acids of castor and ergot oil; Used in contraceptive jellies; [Merck Index] A major component of castor oil in which it is believed to be the active purgative agent; Used in Turkey red oils and for textile finishing; Also used as a plasticizer, softener for elastomers, and to make other products; [HSDB]

Textiles (Printing, Dyeing, or Finishing) [Category: Industry]

Noncosmetic uses of ricinoleic acid: turkey red oil, textile finishing, source of sebacic acid and heptanol, ricinoleate salts, and 12-hydroxystearic acid.

Surfactants and skin-conditioning agents in cosmetic products.

Polyanhydrides synthesized from pure ricinoleic acid half-esters with maleic and succinic anhydrides possess desired physicochemical and mechanical properties for use as drug carriers.

(1979) No Data

(1981) No Data

(1979) No Data

(1981) No Data

2023: <25,000 lb

(1977) AT LEAST 4.58X10+8 GRAMS

(1981) No Data

Production volumes for non-confidential chemicals reported under the Inventory Update Rule. [Table#5474]

One of the simplest methods for obtaining ricinoleic acid is the hydrolysis of castor oil. Ricinoleic acid may then be separated from hydrolyzed castor oil by successive additions of urea (ie, urea complexing). According to a more recent source, ricinoleic acid results from the saponification of castor oil.

Saponification of castor oil.

Fractional distillation of hydrolyzed castor oil

9-Octadecenoic acid, 12-hydroxy-, (9Z,12R)-: ACTIVE

An 18-carbon hydroxylated fatty acid comprising 87-90% weight of castor oil.