Isopropylpalmitat

SRP: Criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

SRP: The scientific literature for the use of contact lenses by industrial workers is inconsistent. The benefits or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.

... Oxaprozin, nimesulide, gliclazide, and ribavirin ... were selected to assess the enhancing activity of pre-treatment solutions consisting of isopropyl palmitate (IP) in ethanol (5%, 10%, 15%and 20%, w/w, respectively) across excised rat skin using Franz diffusion cells and HPLC detection. All pre-treatment solutions produced a significant increase in the flux and permeation of all four penetrants (p<0.001) and a relationship between penetrant lipophilicity and enhancement effect was observed. The general order of IP effectiveness at concentration was 20%>15%>10%>5% (w/w). The lag-time of drugs did not significantly change except for ribavirin.

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 4.0X10+4(SRC), determined from a structure estimation method(2), indicates that isopropyl palmitate is expected to be immobile in soil(SRC). Volatilization of isopropyl palmitate from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 4.66X10-2 atm-cu m/mole(SRC), using a fragment constant estimation method(3). However, adsorption to soil is expected to attenuate volatilization(SRC). Isopropyl palmitate is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 5.59X10-5 mm Hg at 25 °C(4). Biodegradation may be an important environmental fate process for isopropyl palmitate, as suggested by the rapid biodegradation of structurally similar long-chain fatty acid esters(5-7).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 4.0X10+4(SRC), determined from a structure estimation method(2), indicates that isopropyl palmitate is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 4.66X10-2 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 5.1 hours and 6.8 days, respectively(SRC). However, volatilization from water surfaces is expected to be attenuated by adsorption to suspended solids and sediment in the water column(SRC). The volatilization half-life from a model pond is about 11 months when adsorption is considered(6). According to a classification scheme(6), an estimated BCF of 910(SRC), from an estimated log Kow of 8.16(7) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is high, provided the compound is not metabolized by the organism(SRC). An estimated base-catalyzed second-order hydrolysis rate constant of 2.14X10-2 L/mole-sec(SRC) corresponds to half-lives of 10 years and 1 year at pH values of 7 and 8, respectively(8). Biodegradation may be an important environmental fate process for isopropyl palmitate, as suggested by the rapid biodegradation of structurally similar long-chain fatty acid esters(9-11).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), isopropyl palmitate, which has a vapor pressure of 5.59X10-5 mm Hg at 25 °C(2), is expected to exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase isopropyl palmitate 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 17 hours(SRC), calculated from its rate constant of 2.21X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Particulate-phase isopropyl palmitate may be removed from the air by wet or dry deposition(SRC). Isopropyl palmitate does not contain chromophores that absorb at wavelengths >290 nm(4), and therefore is not expected to be susceptible to direct photolysis by sunlight(SRC).

Using a structure estimation method based on molecular connectivity indices(1), the Koc of isopropyl palmitate can be estimated to be 4.0X10+4(SRC). According to a classification scheme(2), this estimated Koc value suggests that isopropyl palmitate is expected to be immobile in soil.

/HUMAN EXPOSURE STUDIES/ Twenty-five adult subjects of unspecified age, sex, and race participated in a photo-contact allergenicity study of a bath oil containing 45.6% isopropyl palmitate. Applications of 5 uL/sq cm of the undiluted test material were repeated twice a week for a total of six applications. The test site remained occluded for 24 hours after each application, and the area was irradiated with a Xenon Solar Simulator (25-30 mW/sq cm) following the removal of each patch. A challenge application with irradiation was made 10 days after the last induction exposure. No instances of photocontact allergenicity were reported, and it was concluded that this formulation is "unlikely to present a risk of photo-contact allergenicity under conditions of normal use."

/HUMAN EXPOSURE STUDIES/ A phototoxicity study of a bath oil formulation containing 45.6% isopropyl palmitate was conducted on 10 normal adult subjects of unreported age, sex, and color. Applications of 5 uL/sq cm of the undiluted test material were made under occlusive patches, and the application sites were irradiated with a Xenon Solar Simulator (25-30 mW/sq cm) after six and 24 hours of contact. No instances of phototoxicity were reported. It was concluded that this formulation is "unlikely to present a risk of phototoxicity under conditions of normal intended use."

/HUMAN EXPOSURE STUDIES/ Kligman's modified maximization procedure was used on 25 subjects to test an undiluted sample of a bath oil formulation containing 45.6% isopropyl palmitate. All patch tests were negative, and it was concluded that, 'based on the maximization scale, the material would be considered the lowest grade, weak potential sensitizer and would be unlikely to present a risk of contact sensitization under conditions of normal intended use."

/HUMAN EXPOSURE STUDIES/ One hundred two men and women of unspecified race participated in a modified Draize-Shelanski repeated insult patch test which was use to ascertain the irritation and sensitization potential of isopropyl palmitate. Approximately 0.1 mL of undiluted isopropyl Palmitate was dispersed onto an absorbent non-woven cotton swatch, 20 x 20 mm, which was then applied to the upper back under an adhesive bandage. The patches were applied three time a week for three weeks and were left in place for 24 hours at each application. Reactions were scored on a 0-4 irritancy scale 24 hours after patch removal. Seventeen days after the last induction patch was removed, a 24-hour challenge application of the test material was made; 24 an 48 hours following the removal of these applications, the challenge reactions were graded. Barely perceptible erythema was noted in three subjects after the second induction insult. All other scores in the induction and challenge periods were 0.0, and it was concluded that isopropyl palmitate did not demonstrate potential for inducing allergic sensitization.

For more Human Toxicity Excerpts (Complete) data for Isopropyl palmitate (8 total), please visit the HSDB record page.

AEROBIC: By analogy to chemically similar long chain fatty acid esters that were rapidly degraded by mixed sewage sludge(1,2,3), biodegrdataion may be an important environmental fate process for isopropyl palmitate under aerobic conditions(SRC).

An estimated BCF of 910 was calculated in fish for isopropyl palmitate(SRC), using an estimated log Kow of 8.16(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is high(SRC), provided the compound is not metabolized by the organism(SRC).

The Henry's Law constant for isopropyl palmitate is estimated as 4.66X10-2 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that isopropyl palmitate is expected to volatilize rapidly from water surfaces(2). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(2) is estimated as 5.1 hours(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(2) is estimated as 6.8 days(SRC). Isopropyl palmitate's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). However, volatilization from water surfaces is expected to be attenuated by adsorption to suspended solids and sediment in the water column. The volatilization half-life from a model pond is about 11 months when adsorption is considered(3). Isopropyl palmitate is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 5.59X10-5 mm Hg(4).

/LABORATORY ANIMALS: Acute Exposure/ For one hour, ten adult male and female albino rats were exposed to an aerosol of isopropyl palmitate in an inhalation chamber. The spray was directed away from the nasal and ocular areas and circulated throughout the chamber for the duration of the exposure. The maximum aerosolization of 200 mg/L achieved prior to the test was maintained throughout the exposure period. The test animal did not exhibit any toxic symptoms during the 14-day post-exposure observation period; nor did gross autopsies produce any significant findings. The acute toxic dose by inhalation was shown to be greater than 200 mg/L of air.

/LABORATORY ANIMALS: Acute Exposure/ The Draize rabbit eye irritation procedure was used to evaluate isopropyl palmitate in five separate studies. In each, 0.1 mL of undiluted isopropyl palmitate was instilled into the conjuctival sacs of adult albino rabbits. One eye was treated in each animal, while the other remained untreated and served as a control. Irritative effects were scored at 24, 48, and 72 hours according to the method of Draize. In one study, nine rabbits were divided into three groups of three animals each. While the treated eyes of group one remained unwashed, those of the other two groups were washed with 20 mL of lukewarm water, one at two seconds the other at four seconds after the test material had been instilled. There were no signs of irritation, and all scores were 0.0. In another study, the eyes of six rabbits remained unwashed after treatment and the Draize Ocular Irritation Index (OII) was 0.0. The six rabbits tested in the third study gave an OII of 0.3 out of a possible total of 110 at 24 hours. At the 48 and 72-hour gradings, all scores were 0.0. In the fourth study, six rabbits were used, and OIIs of 2.33, 0.67, and 0.33 were obtained at 24, 48, and 72 hours, respectively. The fifth study was conducted on four samples of isopropyl palmitate. The resultant OIIs ranged from 3.33 to 6.50 at 48 hours. (An OII of less than 10 on the Draize scale indicates that the compound does not cause any significant injury to the rabbit eye mucous membrane.

/LABORATORY ANIMALS: Acute Exposure/ The Draize primary skin irritation technique was used to evaluate isopropyl palmitate in five separate studies. In each, single doses of 0.5 g or 0.5 mL of the undiluted ingredient were applied under occlusive patches on clipped areas of intact and abraded skin of six albino rabbits. Cutaneous reactions were graded at 24 and 72 hours, and the Primary Irritation Index (PII)s were calculated by averaging the means of the 24- and 72 hour readings. The PIIs in the first four studies were determined to be 0.0, 0.38, 0.6, and 0.92. In the fifth study, each of four samples of isopropyl palmitate was assayed twice, and the eight resultant PIIs ranged from 0.25 (nonirritating) to 1.25 (slightly irritating).

/LABORATORY ANIMALS: Acute Exposure/ An acute dermal toxicity study on isopropyl palmitate was conducted with six albino rabbits (3M, 3F). The trunk skin was clipped free of hair, and in three animals the epidermis was abraded. The trunks were then enclosed in clear polyethylene sleeves, under which 2.0 mL/kg of isopropyl palmitate was deposited onto the skin. Following dosing, the rabbits were immobilized for 24 hours, after which time the sleeves and excess material were removed. The skin was cleaned and examined for gross changes. No erythema, edema, or other outward signs of toxicity were noted for two weeks.

The rate constant for the vapor-phase reaction of isopropyl palmitate with photochemically-produced hydroxyl radicals has been estimated as 2.21X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 17 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). A base-catalyzed second-order hydrolysis rate constant of 2.14X10-2 L/mole-sec(SRC) was estimated using a structure estimation method(2); this corresponds to half-lives of 10 years and 1 year at pH values of 7 and 8, respectively(2). Isopropyl palmitate does not contain chromophores that absorb at wavelengths >290 nm(3), and therefore is not expected to be susceptible to direct photolysis by sunlight(SRC).

Drug products containing certain active ingredients offered over-the-counter (OTC) for certain uses. A number of active ingredients have been present in OTC drug products for various uses, as described below. However, based on evidence currently available, there are inadequate data to establish general recognition of the safety and effectiveness of these ingredients for the specified uses: isopropyl palmitate is included in skin protectant drug products.