Contract No. IOM The National Academies HEALTH EFFECTS OF PROJECT SHAD CHEMICAL AGENT: DIETHYLPHTHALATE [CAS # ]

Transcription

1 The National Academies HEALTH EFFECTS OF PROJECT SHAD CHEMICAL AGENT: DIETHYLPHTHALATE [CAS # ] Prepared for the National Academies by The Center for Research Information, Inc Brookville Rd Silver Spring, MD (301) cri@ix.netcom.com 2004

2 ACKNOWLEDGEMENTS Submitted to Dr. William Page, Program Officer, Advisory Panel for the Study of Long-term Health Effects of Participation in Project SHAD (Shipboard Hazard and Defense), Institute of Medicine, the National Academies. This report is subject to the copyright and reproduction arrangements defined in of the National Academies. This report and any supplements were prepared by the Center for Research Information, Inc. which is solely responsible for its contents. Although this draft is the definitive submission on its subject matter, the Center for Research Information recognizes its ethical and contractual obligation to update, revise, or otherwise supplement this report if new or necessary information on its subject matter should arise, be requested, or be ascertained during the contract period. The Principal Investigator wishes to acknowledge and thank Matthew Hogan, Linda Roberts, Lawrence Callahan, Judith Lelchook and Emnet Tilahun for research assistance, editorial content assistance, and project input. Principal Investigator: Victor Miller Text Draft & Editing: Victor Miller & Matthew Hogan Project Manager: Matthew Hogan Administration: Linda Roberts ii

3 SPECIAL NOTE ON PSYCHOGENIC SEQUELAE OF PERCEIVED EXPOSURE TO BIOCHEMICAL WARFARE AGENTS This report deals primarily with the biological health challenges engendered by the agent that is the subject of the report. Nevertheless, this report also incorporates, by reference and attachment, a supplement entitled "Psychogenic Effects of Perceived Exposure to Biochemical Warfare Agents". The supplement addresses and describes a growing body of health effects research and interest centered upon the psychogenic sequelae of the stress experienced personally from actual or perceived exposure to chemical and biological weaponry. Because awareness of exposure to agents in Project SHAD logically includes the exposed person also possessing a perception of exposure to biochemical warfare agents, the psychogenic health consequences of perceived exposure may be regarded as additional health effects arising from the exposure to Project SHAD agents. This reasoning may also apply to simulants and tracers. Therefore, a general supplement has been created and submitted under this contract to address possible psychogenic effects of perceived exposure to biological and chemical weaponry. Because such health effects are part of a recent and growing public concern, it is expected that the supplement may be revised and expanded over the course of this contract to reflect the actively evolving literature and interest in the issue. iii

4 TABLE OF CONTENTS I. EXECUTIVE SUMMARY.. 1 II. BACKGROUND DATA. 3 Identification & Physical Chemistry 4 Manufacture & Use 4 Kinetics 4 III. HEALTH EFFECTS/TOXICITY 6 Overview. 6 Acute/Subchronic/Chronic Concerns.. 7 Reproductive Toxicity 8 Carcinogenicity.. 9 Genotoxicity 10 IV. PSYCHOGENIC EFFECTS. 11 V. TREATMENT & PREVENTION.. 12 VI. SECONDARY SOURCE COMMENT 13 VII. BIBLIOGRAPHY WITH ABSTRACTS.. 14 iv

5 I. EXECUTIVE SUMMARY Diethylphthalate (more commonly rendered in the scientific literature as two words diethyl phthalate ) is a phthalic acid ester with the chemical formula C 12 H 14 O 4, and commonly identified by Chemical Abstracts Service (CAS) registry number It ordinarily appears as a bitter-tasting colorless or water-white liquid with no odor, or a slight aromatic odor. It is slightly soluble in water, while also soluble in alcohol, ether, benzene, and acetone. Diethylphthalate is miscible with vegetable oils, esters, and aromatic hydrocarbons. It is manufactured by refluxing one equivalent of phthalic anhydride with a greater than two-fold excess of ethanol in the presence of one percent of concentrated sulfuric acid. It is also classed as a phthalic anhydride ester (PAE). Diethylphthalate is a widely encountered compound in daily life. Automobile parts, toothbrushes, tools, and food packaging are ordinary products in which one can frequently find diethylphthalate. Aspirin, insecticides, and cosmetics can also contain it. The most common industrial use for diethylphthalate is as a plasticizer -- an agent for making plastics more flexible. In Project SHAD, diethylphthalate was used as a simulant for VX Nerve Agent. Because of its common use in so many household and personal consumer products, exposure through many pathways (oral, dermal, respiratory) has been studied. The Threshold Limit Value for diethylphthalate of the American Conference of Governmental Industrial Hygienists (ACGIH) is 5.0mg/m 3 based on an 8-hour workday time-weighted average. The pharmacology and kinetics of diethylphthalate exposure indicate slow absorption by the skin, the metabolic conversion of absorbed diethyphthalate into ethanol and the monoester monoethyl phthalate, followed by rapid excretion, mostly in the urine. The effects of diethylphthalate are fairly extensively studied. The chemical shares with other phthalates the characteristic of being among the least toxic of substances in industrial use. In vivo human studies or case reports of serious direct physiological insult as a result of diethylphthalate exposure are not to be found, with the exception of mucous membrane/pulmonary irritation, or a general anesthetic effect at very high concentrations/doses, along with unusual sensitive skin reactions in exceptional sensitized individual cases. An in vitro study on a human skin model did produce a strong cytotoxic reaction but this has not been duplicated in vivo. Animal studies provide powerful corroboration of diethylphthalate s low toxicity. Only very high acute oral doses have produced lethality in animals. Otherwise, non-toxic systemic effects usually seen in animal testing are decreased weight gain with alterations in liver and kidney size, likely attributable to hypertrophy. Animal studies indicate that diethylphthalate is only mildly or moderately irritating when applied to the skin or the eye. 1

6 Evidence of carinogenicity is at best equivocal. In rodent studies a carcinoma/adenoma positive dose-response versus control results was found in only one sex of one species, and the response did not differ significantly from a historical mean for the species and gender. Evidence of genotoxicity is also weak, with only in vitro sister-chromatid exchanges (SCE) a confirmed effect, but these occurred only in the presence of an S9 fraction from a sensitive species in which a correlation between SCEs and carcinogenicity is regarded as tenuous. Both the Environmental Protection Agency (EPA) and ACGIH regard diethylphthalate to be a substance without evidence of cancer risk [EPA class D; ACGIH class A4]; human case reports or epidemiological study of carcinogenesis from diethylphthalate have not been found. Some concern may exist for toxicity in the reproductive/developmental area. Skeletal abnormalities in rodent offspring have been seen after maternal administration of high doses. Chicken embryos die at a faster rate after direct injection of diethylphthalate. A lowering of testosterone levels in rodents has been seen following diethylphthalate exposure, though no fertility or testicular damage was seen. A lowering of human sperm motility was observed after direct in vitro administration of diethylphthalate. Concerns have been raised on risks to pregnant human females and offspring in light of the detected presence of significant amounts of diethylphthalate in the blood of pregnant women in urban areas. One comprehensive and relatively recent (2001) review of diethylphthalate toxicity concludes that there are ultimately no toxic endpoints of concern for the substance in regard to acute toxicity, eye irritation, dermal irritation, dermal sensitization, phototoxicity, photoallergenicity, percutaneous absorption, subchronic toxicity, teratogenicity, reproductive toxicity, genetic toxicity, chronic toxicity, carcinogenicity, and potential human exposure. Psychogenic effects specifically of diethylphthalate exposure have not been found in the literature, but the general effects of a perceived exposure to chemical warfare agents are treated in the supplement provided under this contract entitled Psychogenic Effects of Perceived Exposure to Biochemical Warfare Agents. Secondary literature tends to be comprehensive. It appears that the similarity in names and characteristics of the PAE class may cause confusion in reportage of effects, however. 2

7 Identification & Physical Chemistry II. BACKGROUND DATA Project SHAD Chemical Agent Name: Diethylphthalate. CAS#: More Commonly Appearing Name: Diethyl Phthalate Abbreviation: DEP (Common Use), D (Project SHAD) Alternate Names: anozol; 1,2-benzenedicarboxylic acid diethyl ester; o- benzenedicarboxylic acid diethyl ester; carboxylic acid, diethyl ester; diethyl ester phthalic acid; diethyl o-phthalate; diethyl-o-phenylenediacetate; DPX-F5384; estol 1550; ethyl phthalate; NCI-C60048; neantine; palatinol; phthalol; phthalsaeurediaethylester; placidol E (HSDB 2004, RTECS 2004) Chemical Formula: C 12 H 14 O 4 Chemical Structure (CHEMIDplus 2004): Molecular Weight: Specific gravity: (14 o C) Vapor Pressure: 14mm Hg (163 o C) Conversion rate: 9.07 mg/m 3 = 1 ppm Boiling Point: 298 o C Melting Point: o C Sources: HSDB 2004, RTECS 2004; Chem ID/TOXNET Diethylphthalate is classified among the phthalic anhydride esters (PAEs) (Kamrin 1991). 3

8 Diethylphthalate is produced by refluxing one equivalent of phthalic anhydride with a greater than two-fold excess of ethanol in the presence of one percent of concentrated sulfuric acid (Fed. Reg. 60(171): (September 5, 1995) ). Diethylphthalate is soluble in alcohol, ether, acetone, benzene. It is miscible with vegetable oils, ketones, esters, and aromatic hydrocarbons; it is partly miscible with aliphatic solvents. Diethylphthalate is soluble in water at a rate of 1000 mg/l (25 o C). Diethylphthalate in pure form is usually encountered as a stable, usually colorless (but sometimes white), oily liquid with a bitter taste (HSDB 2004, RTECS 2004). Manufacture and Use Eastman Kodak Company and Unitex Chemical Company are the major American manufacturers of diethylphthalate (HSDB 2004). During Project SHAD, diethylphthalate was used as a simulant for VX Nerve Agent (Project ). Diethylphthalate is a widely used chemical in industrial and consumer products. It chief use is as a plasticizer -- an agent for making plastics more flexible. Automobile parts, toothbrushes, tools, and food packaging are ordinary products in which one can often find diethylphthalate. Aspirin and insecticides may also contain it (HSDB 2004). Because of diethylphthalate s common use in so many household and personal consumer products, human exposure is likely to occur through many pathways (oral, dermal, respiratory). Cosmetic products using diethylphthalate include bath preparations, eye shadows, hair sprays, wave sets, nail polish, nail polish remover, nail extenders, detergents, aftershave lotions, and skin care preparations (HSDB 2004; Api 2001). Diethylphthalate is also used to manufacture celluloid. It has been used as a solvent for cellulose acetate in varnishes; as a fixative for perfumes; as a wetting agent; as a camphor substitute (HSDB 2004; Api 2001). Diethylphthalate has served also as a diluent in polysulfide dental impression materials; and as a solvent for nitrocellulose and cellulose acetate. It is used as a plasticizer in solid rocket propellants and cellulose ester plastics such as photographic films and sheets, blister packaging, and tape applications (HSDB 2004; Api 2001). Kinetics Diethylphthalate can be absorbed through the skin, the lungs, and the digestive tract (Api 2001). Dermal absorption has been extensively studied. In vitro testing by the Research Institute on Fragrance Materials has lead to establishing a human skin steady-state abortion rate of 4

9 mg/cm 2 /hr (Api 2001). Dermal absorption by human skin is about 30 times slower than that of experimental in vitro tissue (Api 2001). Data on inhalation absorption cannot be found. After absorption, diethylphthalate tends to accumulate most in the kidneys and liver, with blood, spleen, and fat cells. Diethylphthalate is usually rapidly metabolized into its monoester, monoethyl phthalate, and ethyl alcohol (ethanol) (Kamrin 1991). The hydrolysis enzymes of diethylphthalate are not well-characterized (Api 2001). Excretion occurs primarily through the urine (WHO 2003; Api 2001). 5

10 III. HEALTH EFFECTS/TOXICITY Overview The toxicology of diethylphthalate has been the subject of extensive study. With other phthalates, it shares the characteristic of being among the least toxic of substances in industrial use. As the discussion in this section will indicate, human or clinical studies reporting serious direct physiological insult as a result of diethylphthalate exposure show only rare, transient, and mostly minor occurrences in high dose situations or with sensitive individuals. These include irritation from heated diethylphthalate, central nervous system depression after heavy exposure, along with rare dermal sensitivity in individuals with a pre-disposition for dermal sensitization A recent (2001) comprehensive review of diethylphthalate toxicity concludes that there are no toxic endpoints of concern in the following areas: acute toxicity, eye irritation, dermal irritation, dermal sensitization, phototoxicity, photoallergenicity, percutaneous absorption, subchronic toxicity, teratogenicity, reproductive toxicity, genetic toxicity, chronic toxicity, carcinogenicity, and potential human exposure (Api 2001). In many experimental tests, the lowest observed effect level exceeds the maximum tested dose. A table in the next subsection below will provide toxicity values found in key studies. Indications of genotoxicity or carcinogenicity have been authoritatively deemed to be at most equivocal and key authorities do not consider diethylphthalate a cancer risk The Threshold Limit Value/Time Weighted Average (TLV-TWA) for diethyphthalate of the American Conference of Government Industrial Hygienists (ACGIH) is 5 mg/m 3 as an 8-hour time weighted average. (WHO 2003). This TLV level in practice amounts to about 50mg inhaled per person each work day for a lifetime (Api 2001). The highest consumer food with diethylphthalate content (presumably from contamination from packaging) in a UK study were quiches, averaging 2-3 mg/kg (human). Nevertheless 4 mg (absolute amount) was found to be the average ordinary human exposure/intake per person per day (Kamrin 1991). Indoor air concentration of diethylphthalate recorded in Tokyo recently was 0.1 µg/m 3 (Otake 2004). In general, significant systemic toxicity is not indicated -- high dose oral subchronic and chronic tests on rats shows only gains in liver weight as an effect, which was attributable to hypertophy and not toxicity, along with moderate decreased weight gain. (Api 2001; Kamrin 1991) Guinea pigs experienced only slight liver and kidney damage when exposed orally to a high dose of 1 mg/kg daily for up to 12 consecutive days. 6

11 Acute/Subchronic/Chronic Concerns There is a broad consensus in the literature that diethylphthalate is generally of low acute toxicity. (NTP 1995; Api 2001; WHO 2003). The following Lethal Dose 50 percent kill (LD 50 ) values tend to support this: ROUTE ANIMAL LD 50 Oral guinea pig 8,600 mg/kg Oral mouse 6,172 mg/kg Oral rat 8,600 mg/kg Oral rabbit 1 gm/kg Intraperitoneal mouse 2,749 mg/kg Intraperitoneal rat 5,058 µl/kg Subcutaneous guinea pig 3 gm/kg Unreported route guinea pig 3 gm/kg Unreported route mouse 8,600 mg/kg Unreported route rat 9,500 mg/kg (Adapted from RTECS 2004) Human toxic effect lowest levels (Lowest Observed Adverse Effect Levels -- LOAELs) have been reported to show at these concentrations: Oral Human 357 µl/kg Inhalation Human 1,000 mg/m3 (Adapted from RTECS 2004) In humans, coughing and lacrimation occur at the inhalation dose 1.0 g/m 3 (note: 200 times the Threshold Limit Value (TLV)). Miosis, dyspnea, amd general anesthetic effects followed human oral exposure at the dose level above. Central nervous system depression signs were seen in the animals prior to death. (RTECS 2004; HSDB 2004) Acute doses in the range of g/kg delivered intravenously are the lowest levels for lethality in mice and rabbits. Dermal exposure of rats at levels lower than 11g/kg, the highest dose administered, failed to kill any (Api 2001). No studies or record of human fatality from acute or chronic exposure have been found. Animal and human studies indicate at most mild to moderate irritant toxicity to skin and eyes. An administration to clipped rat skin of 2ml/kg at 6 hour intervals each day for two weeks evoked erythema, desquamation, and mild epidermal thickening. Some irritation was found in a 24 hour epicutaneous test on guinea pigs; moderate irritation only was 7

12 found on closed patch tests on rabbit skin. No effects occurred in a semiocclusive patch test of exposure to 0.5 ml of diethylphthalate for four hours (Api 2001). Intradermal administration to test animals have produced significant irritation. Ocular exposure in one standard rabbit test elicited no obvious irritation (Lawrence 1975). Other rabbit tests have shown some transitory severe conjunctival irritation, but the use of the solvent ethanol may have been to blame (Api 2001). Humans showed no primary irritation from applications of undiluted diethylphthalate epicutaneously. An in vitro model of human skin showed marked cytotoxicity but this could not be duplicated in vivo (Api 2001). A computer mouse containing diethylphthalate appears to have induced dermatitis in the hands of two women according to one case study (WHO 2003). No dermal sensitization was elicited in guinea pigs and humans not prone to allergic reactions or previously exposed have shown no little or no sensitization in volunteer testing and case studies. A small proportion (1/30) workers previously exposed to diethylphthalate exhibited some dermatitis (WHO 2003). No significant photoxicity or photoallerginicity was elicited in tests on human volunteers (Api 2001). Chronic studies reveal that at very high doses (> 25g/kg/day) organ weight loss and decreased weight gain are typically noted (RTECS 2004; Api 2001). Reports describing cases of human toxic effects from chronic exposures were not found. Chronic rodent testing also cited below in the subsection on carcinogenesis indicated no general toxic effects from exposure (WHO 2003; NTP 1995). Study or reports of neurological toxicity have not been found, other than a general central nervous system depression at high toxic doses (Api 2001). Two studies found no toxic pathology in the brain after administration orally of up to 3.7 g/kg in rats or mice (Brown et al 1978; WHO 2003). Reproductive Toxicity Concerns may exist in the area of reproductive toxicity. Administration of diethylphthalate to rats and mice has led to the increase in skeletal defects or rib number alteration in offspring. (WHO 2003; Field et al 1993; Kamrin 1991; Singh et al 1972). Testing of rats yielded no embryotoxicty or teratogenicity except an extra rib when administration of up to 3.2g/kg (oral) diethylphthalate and 5.6 g/kg (percutaneous) diethylphthalate occurred at the time of organogenesis. Fetal weight was lower in the high-dose group (WHO 2003). 8

13 Direct injections of diethylphthalate (0.025 ml) into chicken eggs prior to embryonic stage development has induced an increased level of deaths, with a small percentage of malformations among the survivors (Api 2001).. A multigeneration developmental study of mice noted no signs of toxicity/defects in the F 0 generation after high oral dosing of 3.6g/kg for 14 weeks after cohabitation, and none also in the subsequent (unexposed) generation F 1, except for a reduced number of pups per litter, mild inhibition of body weight gain, reduction by 30% in epididymal sperm concentration, and moderate increase in liver and prostate weight (WHO 2003; NTP 1984). A NOAEL (no observed adverse effect level) for reproductive toxicity after administration for over 14 weeks after gestation in pregnant SD rats was established at 750 mg/kg per day (WHO 2003). No study indicating human maternal or developmental toxicity have been found. Concerns have been raised, nonetheless, by the substantial presence of diethylphthalate in the blood of pregnant women in urban areas (Adibi et al. 2003). There has been some indication of possible detrimental effects by diethylphthalate on the male reproductive system. In the multigenerational study cited above a reduction of 30% in epididymal sperm concentration and an increase in prostate weight were noted. Human sperm treated in vitro showed impairment in motility after less than 18 minutes of exposure (Fredricsson et al 1993). Testosterone levels in rat testes and serum decreased after an oral exposure to 2% diethylphthalate in the diet. Nevertheless, no other toxic male reproductive injury was found anywhere in the rat, including no testicular damage or Sertoli cell impairment (Api 2001). Mice showed no reproductive system effects of any kind at the same level of dosing (Api 2001). Leydig cells showed ultrastructural changes in male rats receiving 2g/kg daily for two days. Smooth endoplasmic reticulum focal dilation and vesiculation, mitochondrial swelling, and increased macrophage activity associated with the Leydig cell surface were noted (Jones et al1993; WHO 2003). Enormous oral doses induced some testicular weight changes in rats These occurred only at a level of 44g-354g/kg delivered daily over 2-16 weeks (Brown et al 1978; RTECS 2004). In vivo human studies or reports of testicular or male reproductive toxicity from diethylphthalate have not been found. Carcinogenicity Key authorities deem the available evidence insufficient to declare diethylphthalate carcinogenic. The EPA classifies diethyl phthalate as class D, unclassifiable as to human carcinogenicity. The ACGIH classifies diethylphthalate as A4, not classifiable as a human carcinogen (WHO 2003; US EPA 2004). 9

14 Evidence of carcinogenicity remains at best equivocal (WHO 2003; Api 2001). A National Toxicology Program dermal study found no evidence of site-specific dermal carcinogenicity in male and female rats in 2 year dermal administration studies applying up to 1.6 g/kg of diethylphthalate per day (Api 2001). Another dermal test of up to 1.1 g/kg per day of diethylphthalate in acetone for 103 weeks in both rats and mice turned up no neoplasia at the site of application, but at high doses there was some increase in combined hepatocellular adenoma or carcinoma in male mice. A non-dose-related increase in carcinomas occurred in female mice. This has been regarded as equivocal as the rate among males was similar to the historical neoplasm mean rate in males of that mice strain and because the female response was not doserelated. Additionally the results were not duplicated in the tested rat species. (NTP 1995; Api 2001; WHO 2003) Diethylphthalate was also dermally tested over a period of one year with cancer promoter 12-O-tetradecanoylphorbol-13-acetate and with initiator 7,12-dimethylbenz[a]anthracene. No initiator or promoter activity was observed (NTP 1995). Genotoxicity Diethylphthalate was found not to be mutagenic in Salmonella strains TA 98, TA 100, TA 1535 or TA 1537 with or without liver fraction S9 (NTP 1995). No in vivo studies have been reported (WHO 2003). Chromosomal aberrations were also absent in Chinese hamster ovary cells with and without S9 liver fraction. Nevertheless, sister-chromatid exchanges (SCEs) were noted at µg/ml concentrations but only with rat liver S9. While this was regarded as some evidence for potential DNA damage in vivo, the NTP cautioned that the endpoint is highly sensitive and it does not correlate well with carcinogenicity in rodents (NTP 1995). 10

15 IV. PSYCHOGENIC EFFECTS There are no known studies addressing psychogenic effects of exposure to diethylphthalate. The general effects of perceived exposure to chemical or biological warfare agents are treated in the supplement Psychogenic Effects of Perceived Exposure to Biochemical Warfare Agents. 11

16 V. TREATMENT/PREVENTION Standard protection procedures, and limitations of them, regarding diethyl phthalate overexposure is provided below (Mallinckrodt Baker Inc. 2004): Ventilation System: A system of local and/or general exhaust is recommended to keep employee exposures below the Airborne Exposure Limits. Local exhaust ventilation is generally preferred because it can control the emissions of the contaminant at its source, preventing dispersion of it into the general work area. Personal Respirators (NIOSH Approved): If the exposure limit is exceeded and engineering controls are not feasible, a half facepiece particulate respirator (NIOSH type P95 or R95 filters) may be worn for up to ten times the exposure limit or the maximum use concentration specified by the appropriate regulatory agency or respirator supplier, whichever is lowest.. A full-face piece particulate respirator (NIOSH type P100 or R100 filters) may be worn up to 50 times the exposure limit, or the maximum use concentration specified by the appropriate regulatory agency, or respirator supplier, whichever is lowest. Please note that N filters are not recommended for this material. For emergencies or instances where the exposure levels are not known, use a fullfacepiece positive-pressure, air-supplied respirator. WARNING: Air-purifying respirators do not protect workers in oxygen-deficient atmospheres. Skin Protection: Wear protective gloves and clean body-covering clothing. Eye Protection: Use chemical safety goggles and/or full face shield where dusting or splashing of solutions is possible. Maintain eye wash fountain and quick-drench facilities in work area. Exposure to diethylphthalate has rarely been reported as harmful so no systematic treatment methods specific to diethylphthalate are reported. TOXNET suggests applying the emergency medical treatment protocol for dibutyl phthalate (HSDB 2004). 12

17 VI. SECONDARY SOURCE COMMENT Secondary literature tends to be comprehensive. The International Agency for Research on Cancer (IARC) provides no evaluation for diethylphthalate (CAS ). (See Occasional references to gastrointestinal irritation (nausea) from oral exposure arise in the literature, including Project SHAD s Glossary (Project ; Mallinckrodt Baker 2004). The Merck Index claims polyneuritis as a possible effect (O Neil 2001). But no primary information on such toxic effects has been found, nor have they been reported in recent reviews (WHO 2003; Api 2001; NTP 1995). It is suggested that the insertion of dibutyl phthalate s medical handling procedures in TOXNET s discussion of diethylphthalate treatment inside its diethylphthalate HSDB monograph, and which includes statements describing dibutyl phthalate s toxic effects of nausea and polyneuritis, may be responsible for such confusion, or at least reflect a pattern of easy confoundment that can give rise to such errors (HSDB 2004). One author notes aptly that the similarity in common abbreviations and in the productive uses of the two phthalic acid esters DEP (diethylphthalate) and DEHP (di (ethylhexyl) phthalate) can lead to confusion (Kamrin 1991). 13

18 VII. BIBLIOGRAPHY WITH ABSTRACTS {The following bibliography may contain supplementary material beyond those cited in the text. Abstracts are reproduced without alteration from how they are provided in their original source or database. Errors and defects of form, content, or style are strictly those of the original source.} Anonymous Reproductive toxicology. Diethylphthalate. Environ.Health Perspect. 105 Suppl 1: Adibi, et al Prenatal exposures to phthalates among women in New York City and Krakow, Poland. Environ.Health Perspect. 111(14): Experimental evidence has shown that certain phthalates can disrupt endocrine function and induce reproductive and developmental toxicity. However, few data are available on the extent of human exposure to phthalates during pregnancy. As part of the research being conducted by the Columbia Center for Children's Environmental Health, we have measured levels of phthalates in 48-hr personal air samples collected from parallel cohorts of pregnant women in New York, New York, (n = 30) and in Krakow, Poland (n = 30). Spot urine samples were collected during the same 48-hr period from the New York women (n = 25). The following four phthalates or their metabolites were measured in both personal air and urine: diethyl phthalate (DEP), dibutyl phthalate (DBP), diethylhexyl phthalate (DEHP), and butyl benzyl phthalate (BBzP). All were present in 100% of the air and urine samples. Ranges in personal air samples were as follows: DEP ( microg/m3), DBP ( microg/m3), DEHP ( microg/m3), and BBzP ( microg/m3). The mean personal air concentrations of DBP, di-isobutyl phthalate, and DEHP are higher in Krakow, whereas the mean personal air concentration of DEP is higher in New York. Statistically significant correlations between personal air and urinary levels were found for DEP and monoethyl phthalate (r = 0.42, p < 0.05), DBP and monobutyl phthalate (r = 0.58, p < 0.01), and BBzP and monobenzyl phthalate (r = 0.65, p < 0.01). These results demonstrate considerable phthalate exposures during pregnancy among women in these two cohorts and indicate that inhalation is an important route of exposure. Agarwal, et al Mutagenicity evaluation of phthalic acid esters and metabolites in Salmonella typhimurium cultures. J.Toxicol.Environ.Health. 16(1): The mutagenic potential of dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), and di-2-ethylhexyl phthalate (DEPH), as well as metabolites of DEHP- 14

19 -i.e., mono-2-ethylhexyl phthalate (MEHP), 2-ethylhexanol (2-EH), and phthalic acid (PA)--were tested in Salmonella typhimurium cultures using the Ames test procedure. The compounds were tested on strains TA98, TA100, TA1535, TA1537, TA1538, and TA2637 for base-pair substitution or frameshift-type mutations. Spot tests yielded negative responses for all compounds with the strains tested. Each compound was tested for a dose-effect relationship in the TA98, TA100, TA1535, and TA1538 systems. DEP and DBP exhibited a mildly positive response in both TA100 and TA1535 cultures, and DMP showed a similar response in TA1535. Normalization of the data for cytotoxicity of DMP suggests TA100 has a mildly positive effect. The higher doses of these compounds exhibited some cytotoxic effects. The mutagenic effects were apparently abolished by the addition of S9 fraction in TA100 and TA1535 cultures, while no effect, other than cytotoxicity, was observed in the TA98 and TA1538 systems. DEHP, MEHP, 2-EH, and PA exhibited no mutagenicity in any of the strains of Salmonella typhimurium tested, with or without S9 metabolic activation. MEHP and 2-EH, however, exhibited a moderate cytotoxic effect in most cultures. Api Evaluation of the dermal subchronic toxicity of phenoxyethyl isobutyrate in the rat. Food Chem.Toxicol. 42(2): Phenoxyethyl isobutyrate (PEIB) is a fragrance and food ingredient that has been granted GRAS status and approved by the FDA for food use. The present studies investigated the dermal absorption parameters and subchronic toxicity of PEIB. For the absorption, distribution and elimination study, Sprague-Dawley rats received a dermal application of 2-[ring U 14C]-PEIB under occlusion for 6 h. PEIB was diluted in diethyl phthalate (DEP) to administer, a total application volume of 2 ml/kg, concentrations of 0.5, 5 and 50% ( congruent with 10, 100 and 1000 mg PEIB/kgBW). Approximately 61-69% of the applied dose was recovered from the dressing and skin surface washing procedure performed after 6-h exposure. By 72 h post dose, systemic elimination of radioactivity was congruent with 18 to 19% of the absorbed dose via the urine with small amounts also found in the feces (<1.0%). Terminal (72 h) tissue analysis showed that % of the applied dose of radioactivity was retained in the carcass with low levels (</=0.03%) measured also in the liver, kidney and gastrointestinal tract. Plasma levels increased in a dose-related manner, with concentrations equal to 0.02, 0.2 and 2.0 microg equiv/ml from low to high dose, respectively. The total recovery for these studies ranged from 92.2 to 96.2% of the dermally applied radioisotope. In a 13-week subchronic rat toxicity study, daily dermal applications of PEIB were made under occlusion for 6 h. All groups were dosed at a constant 2 ml/kgbw volume of PEIB in the DEP vehicle at concentrations calculated to administer 0, 100, 300 or 1000 mg PEIB/kgBW/day. Clinical observations, assessments of skin irritation, hematology, and blood chemistry, necropsy, and gross and histopathologic evaluation of tissues demonstrated no treatment-related 15

20 effects. The local skin irritation and systemic toxicity no-observed-effect-levels (NOELs) for PEIB in this study were determined to be >1000 mg/kgbw/day. Api Sensitization methodology and primary prevention of the research institute for fragrance materials. Dermatology. 205(1): The Research Institute for Fragrance Materials Inc. (RIFM) has approached sensitization studies with fragrance materials as primary prevention of sensitization in the healthy, normal population. Secondary prevention, or avoidance of elicitation, most often suggested by dermatologists for patients presenting with dermatitis, has not been part of its program effort. Historically, RIFM evaluated the sensitization potential of fragrance materials using the human maximization test method; no animal models were used. In general, petrolatum was used as the vehicle. This is a harsh procedure whose main use may provide a measure of the uppermost limits of sensitization. Treating skin with sodium lauryl sulfate may be problematic and finding a laboratory to conduct the study may also be difficult. In addition, using a human predictive test method for both hazard and safety assessments is not ideal. The current practice involves a hazard assessment using an animal model, followed by a safety assessment in a human repeated-insult patch test (HRIPT). The animal test method is used to identify the sensitization potential and a no-effect level. Following a review of the no-effect level and the maximum skin level, a safety assessment in humans can be conducted. RIFM also modified the original vehicle used in sensitization testing, since petrolatum presents two major difficulties: solubility and inconsistent effects on skin penetration. Since the greatest exposure to fragrance materials is considered to be from a cologne-type product, ethanol was chosen as a more realistic vehicle. Further modification resulted in combinations of ethanol and diethyl phthalate, due to diethyl phthalate's use in many perfume formulations as a solvent and fluidizer. Human testing should not be conducted as a hazard assessment. If conducted as a safety study, induction of sensitization should be a rare occurrence. Thus, follow-up studies are not meaningful since the number of sensitized volunteers would be low. However, following a series of the RIPTs with various concentrations of hydroxycitronellal, RIFM identified a group of 41 individuals who became sensitized. An extensive 3-phase use study, with 3 diagnostic patch tests and 4 whole-body dermatological examinations showed that most subjects were able to use a bar soap, a moisurizing lotion and cologne-type products with up to 1% hydroxycitronellal. In subjects where sensitization was induced by predictive testing, no serious recurring adverse dermatological conditions developed. Api Toxicological profile of diethyl phthalate: a vehicle for fragrance and cosmetic ingredients. Food Chem.Toxicol. 39(2): Diethyl phthalate (DEP; CAS No ) has many industrial uses, as a solvent and 16

21 vehicle for fragrance and cosmetic ingredients and subsequent skin contact. This review focuses on its safety in use as a solvent and vehicle for fragrance and cosmetic ingredients. Available data are reviewed for acute toxicity, eye irritation, dermal irritation, dermal sensitization, phototoxicity, photoallergenicity, percutaneous absorption, kinetics, metabolism, subchronic toxicity, teratogenicity, reproductive toxicity, estrogenic potential, genetic toxicity, chronic toxicity, carcinogenicity, in vitro toxicity, ecotoxicity, environmental fate and potential human exposure. No toxicological endpoints of concern have been identified. Comparison of estimated exposure (0.73 mg/kg/day) from dermal applications of fragrances and cosmetic products with other accepted industrial (5 mg/m(3) in air) and consumer exposures (350 mg/l in water; 0.75 mg/kg/day oral exposure) indicates no significant toxic liability for the use of DEP in fragrances and cosmetic products.. Berg, et al Diethyl phthalate not dangerous. Am.J.Hosp.Pharm. 48(7): Beving, et al Increased isotransferrin ratio and reduced erythrocyte and platelet volumes in blood from thermoplastic industry workers. Ann.Occup.Hyg. 34(4): Ten women (aged years) and five men (aged years) occupationally exposed to welding fumes of polyacetate containing diethylphthalate in a thermoplastic industry were studied. They had been employed 1-33 years (median: 11 years). Seven women (aged 35-55) and eight men (aged 26-73) acted as unexposed controls. The exposed persons showed increased isotransferrin ratio in blood serum and reduced volumes of erythrocytes and platelets in blood. Blount, et al Levels of seven urinary phthalate metabolites in a human reference population. Environ.Health Perspect. 108(10): Using a novel and highly selective technique, we measured monoester metabolites of seven commonly used phthalates in urine samples from a reference population of 289 adult humans. This analytical approach allowed us to directly measure the individual phthalate metabolites responsible for the animal reproductive and developmental toxicity while avoiding contamination from the ubiquitous parent compounds. The monoesters with the highest urinary levels found were monoethyl phthalate (95th percentile, 3,750 ppb, 2,610 microg/g creatinine), monobutyl phthalate (95th percentile, 294 ppb, 162 microg/g creatinine), and monobenzyl phthalate (95th percentile, 137 ppb, 92 microg/g creatinine), reflecting exposure to diethyl phthalate, dibutyl phthalate, and benzyl butyl phthalate. Women of reproductive age (20-40 years) were found to have significantly higher levels of monobutyl phthalate, a reproductive and developmental toxicant in rodents, than other age/gender groups (p < 0.005). Current scientific and regulatory attention on phthalates has focused almost exclusively on health risks from exposure to 17

22 only two phthalates, di-(2-ethylhexyl) phthalate and di-isononyl phthalate. Our findings strongly suggest that health-risk assessments for phthalate exposure in humans should include diethyl, dibutyl, and benzyl butyl phthalates. Brown, et al Short-term oral toxicity study of diethyl phthalate in the rat. Food Cosmet.Toxicol. 16(5): Cafmeyer, et al Possible leaching of diethyl phthalate into levothyroxine sodium tablets. Am.J.Hosp.Pharm. 48(4): The possible leaching of diethyl phthalate into four currently marketed brands of levothyroxine sodium tablets was investigated. Several strengths of levothyroxine sodium tablets and sizes of containers were used. Samples were analyzed by high-performance liquid chromatography (HPLC) to determine the levothyroxine sodium content and to determine if any unidentified compounds were present. The packaging for the four brands of tablets was also analyzed by using the same HPLC system to determine if any extractable compounds could be detected in the tablets. The potencies of the four brands of tablets were comparable. The tablets from the 100-count container of one brand (brand A) were the only tablets found to contain an unidentified peak in the chromatogram. The desiccants from the bottle showed the same unidentified compound, while the bottle and closure did not yield the peak. Thin-layer chromatography and HPLC identified the peak as diethyl phthalate, a plasticizer in the desiccant. Tablets, bottles, closures, and desiccants for the 1000-count brand A product and all sizes of the other brands were negative for the presence of diethyl phthalate. The desiccants in those containers were from a different manufacturer than the desiccant in the brand A 100-count bottle. Diethyl phthalate in the desiccant in 100-count bottles of brand A levothyroxine sodium tablets appeared to have leached into the tablets. Call, et al An assessment of the toxicity of phthalate esters to freshwater benthos. 2. Sediment exposures. Environ.Toxicol.Chem. 20(8): Seven phthalate esters were evaluated for their 10-d toxicity to the freshwater invertebrates Hyalella azteca and Chironomus tentans in sediment. The esters were diethyl phthalate (DEP), di-n-butyl phthalate (DBP), di-n-hexyl phthalate (DHP), di-(2- ethylhexyl) phthalate (DEHP), diisononyl phthalate (DINP), diisodecyl phthalate (DIDP), and a commercial mixture of C7, C9, and C11 isophthalate esters (711P). All seven esters were tested in a sediment containing 4.80% total organic carbon (TOC), and DBP alone was tested in two additional sediments with 2.45 and 14.1% TOC. Sediment spiking concentrations for DEP and DBP were based on LC50 (lethal concentration for 50% of the population) values from water-only toxicity tests, sediment organic carbon concentration, and equilibrium partitioning (EqP) theory. The five higher molecular 18

23 weight phthalate esters (DHP, DEHP, DINP, DIDP, 711P), two of which were tested and found to be nontoxic in water-only tests (i.e., DHP and DEHP), were tested at single concentrations between 2,100 and 3,200 mg/kg dry weight. Preliminary spiking studies were performed to assess phthalate ester stability under test conditions. The five higher molecular weight phthalate esters in sediment had no effect on survival or growth of either C. tentans or H. azteca, consistent with predictions based on water-only tests and EqP theory. The 10-d LC50 values for DBP and H. azteca were >17,400, >29,500, and >71,900 mg/kg dry weight for the low, medium, and high TOC sediments, respectively. These values are more than 30x greater than predicted by EqP theory and may reflect the fact that H. azteca is an epibenthic species and not an obligative burrower. The 10-d LC50 values for DBP and C. tentans were 826, 1,664, and mg/kg dry weight for the low, medium, and high TOC sediments, respectively. These values are within a factor of two of the values predicted by EqP theory. Pore-water 10-d LC50 values for DBP (dissolved fraction) and C. tentans in the three sediments were 0.65, 0.89, and 0.66 of the water-only LC50 value of 2.64 mg/l, thereby agreeing with EqP theory predictions to within a factor of 1.5. The LC50 value for DEP and C. tentans was >3,100 mg/kg dry weight, which is approximately 10x that predicted by EqP theory. It is postulated that test chemical loss and reduced organism exposure to pore water may have accounted for the observed discrepancies with EqP calculations for DEP Call, et al An assessment of the toxicity of phthalate esters to freshwater benthos. 1. Aqueous exposures. Environ.Toxicol.Chem. 20(8): Tests were performed with the freshwater invertebrates Hyalella azteca, Chironomus tentans, and Lumbriculus variegatus to determine the acute toxicity of six phthalate esters, including dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), butylbenzyl phthalate (BBP), di-n-hexyl phthalate (DHP), and di-2-ethylhexyl phthalate (DEHP). It was possible to derive 10-d LC50 (lethal concentration for 50% of the population) values only for the four lower molecular weight esters (DMP, DEP, DBP, and BBP), for which toxicity increased with increasing octanol-water partition coefficient (Kow) and decreasing water solubility. The LC50 values for DMP, DEP, DBP, and BBP were 28.1, 4.21, 0.63, and 0.46 mg/l for H. azteca; 68.2, 31.0, 2.64, and > 1.76 mg/l for C. tentans; and 246, 102, 2.48, and 1.23 mg/l for L. variegatus, respectively. No significant survival reductions were observed when the three species were exposed to either DHP or DEHP at concentrations approximating their water solubilities. CHEMIDplus Diethyl Phthalate. TOXNET [NLM Database]. [ andle=default&nextpage=jsp/chemidlite/resultscreen.jsp&txtsuperlistid= ] 19

24 Elsisi, et al Dermal absorption of phthalate diesters in rats. Fundam.Appl.Toxicol. 12(1): This study examined the extent of dermal absorption of a series of phthalate diesters in the rat. Those tested were dimethyl, diethyl, dibutyl, diisobutyl, dihexyl, di(2-ethylhexyl), diisodecyl, and benzyl butyl phthalate. Hair from a skin area (1.3 cm in diameter) on the back of male F344 rats was clipped, the [14C]phthalate diester was applied in a dose of 157 mumol/kg, and the area of application was covered with a perforated cap. The rat was restrained and housed for 7 days in a metabolic cage that allowed separate collection of urine and feces. Urine and feces were collected every 24 hr, and the amount of 14C excreted was taken as an index of the percutaneous absorption. At 24 hr, diethyl phthalate showed the greatest excretion (26%). As the length of the alkyl side chain increased, the amount of 14C excreted in the first 24 hr decreased significantly. The cumulative percentage dose excreted in 7 days was greatest for diethyl, dibutyl, and diisobutyl phthalate, about 50-60% of the applied 14C; and intermediate (20-40%) for dimethyl, benzyl butyl, and dihexyl phthalate. Urine was the major route of excretion of all phthalate diesters except for diisodecyl phthalate. This compound was poorly absorbed and showed almost no urinary excretion. After 7 days, the percentage dose for each phthalate that remained in the body was minimal and showed no specific tissue distribution. Most of the unexcreted dose remained in the area of application. These data show that the structure of the phthalate diester determines the degree of dermal absorption. Absorption maximized with diethyl phthalate and then decreased significantly as the alkyl side chain length increased. Field, et al Developmental toxicity evaluation of diethyl and dimethyl phthalate in rats. Teratology. 48(1): Diethyl phthalate (DEP) and dimethyl phthalate (DMP), phthalic acid ester (PAE) plasticizers, were evaluated for developmental toxicity because of reports in the literature that some PAE were embryotoxic and teratogenic. A previous study (Singh et al., '72) suggested that an increased incidence of skeletal defects in rats might result from gestational exposure to DEP ( g/kg) or DMP ( g/kg), ip, on gestational days (gd) 5, 10, and 15. In the current study DEP (0, 0.25, 2.5, and 5%) or DMP (0, 0.25, 1, and 5%) in feed (approximately g/kg/day) were supplied to timed-mated rats from gd 6 to 15. Treatment with 5% DMP resulted in increased relative maternal liver weight. Also, animals exhibited reduced body weight gain during treatment (5% DEP or DMP) and during gestation (5% DEP). Weight gain corrected for gravid uterine weight was also reduced in animals fed 5% DEP. However, high-dose treatment with either DEP or DMP resulted in changes in food and water consumption paralleling the body weight reductions, suggesting that apparent toxic effects on maternal body weight may reflect PAE/feed unpalatability. Treatment with 2.5% DEP resulted in only transient changes in 20

25 body weight during early treatment. The only maternal effects at 0.25 or 1% DMP were minor changes in food and/or water consumption, and there were no effects at 0.25% DEP. Thus, the NOAELs for maternal toxicity were 1% DMP and 0.25% DEP. In contrast to the observed maternal toxicity, there was no effect of DEP or DMP treatment on any parameter of embryo/fetal development, except an increased incidence of supernumerary ribs (a variation) in the 5% DEP group. These results do not support the conclusion of other investigators that DEP and DMP are potent developmental toxicants. Rather, they suggest that the short-chain PAE are less developmentally toxic than PAE with more complex substitution groups, e.g., di(2-ethylhexyl) phthalate, mono(2- ethylhexyl) phthalate, and butyl benzyl phthalate. Foster, et al Effect of DI-n-pentyl phthalate treatment on testicular steroidogenic enzymes and cytochrome P-450 in the rat. Toxicol.Lett. 15(2-3): Treatment of young male rats with dipentyl phthalate (DPP) produced significant decreases in testicular cytochrome P-450, cytochrome P-450 dependent microsomal steroidogenic enzymes (17 alpha-hydroxylase, lyase) and in the maximal binding of a natural substrate (progesterone) to testis microsomes. No effect was demonstrated by this compound on hepatic cytochrome P-450 content. Treatment of animals with a phthalate ester not causing testicular atrophy (diethyl phthalate; DEP) produced no significant changes in any of the parameters measured. This effect on the enzymes responsible for androgen production may be important as a mechanism of action involved in the development of phthalate-induced testicular damage. Fredricsson et al Human sperm motility is affected by plasticizers and diesel particle extracts. Pharmacol Toxicol. 72(2): In order to test various drugs and possibly hazardous compounds on living cells in vitro a system with human spermatozoa was employed. A population of human spermatozoa was transferred into a defined medium by a swim-up procedure or by separation on a Percoll gradient. Such a population is rather homogenous with respect to motility characteristics and was found to be useful for this purpose. Different modes of response were recorded, indicating various effect mechanisms. Effects of various phthalates used as plastic softeners in the production of medical equipment, and extracts from diesel particulate material were recorded. All these compounds interfered with sperm motility in a doseresponse fashion. Immediate effects of phthalates were modest, but upon prolonged exposure effects became more evident. Sperm motility was more affected by diethylhexyl and dibutyl phthalates. Significant effects were noted for the different phthalates with regard both to percent motility and to some of the various qualities of motility, such as velocity, linearity and amplitude of the track. Thus, the pattern of response considering the motion variables was not the same with the different phthalates. With regard to the effects on sperm motion di-n-octyl phthalate seemed to be the least toxic, followed by dibutyl phthalate. The initial effects of diesel particulate extracts were moderate and mainly restricted to percent motile sperm but upon exposure for 18 hr the effects became more pronounced for all the movement variables. 21