chemical information
CAS RN:
00131-11-3
Chemical Class:
Found in these people:
Bill Moyers, Davis Baltz, Lucy Waletsky, Michael Lerner, Sharyle Patton, Monique Harden
Found in these locations:
NJ, USA; Berkeley, CA; Pleasantville, NY; Bolinas, CA; New Orleans, LA
Summary
Found within many consumer products, phthalates are industrial plasticizers that impart flexibility and resilience to plastic, among other uses. Dimethyl phthalate (DMP) is used in insect repellant, plastic, and as a rocket propellant (EWG 2003; Wolff 2007). Exposure to dimethyl phthalate occurs through direct use of products containing this chemical, as well as through inhalation of contaminated air (CDC 2005). In the body, DMP is converted to the metabolite, or breakdown product, monomethyl phthalate (mMeP).
In September 2000, scientists from the Centers for Disease Control and Prevention (CDC) conducted the first accurate measurements of human phthalate exposures, and reported finding phthalates in every one of 289 people tested, at surprisingly high levels (Blount 2000). The latest exposure study from CDC indicates that mMeP, the breakdown product of DMP, is a common contaminant of the human body (CDC 2005). Measurements of mMeP in the urine of over 2,500 Americans indicate that women are more exposed than men, and younger children (ages 6-11) are more exposed than older children (ages 12-19), who are in turn more exposed than adults (CDC 2005). In a recent study of girls age 6 to 8 spearheaded by Mount Sinai School of Medicine, this particular phthalate metabolite was found in 18 of 90 girls tested (Wolff 2007). The European Union has banned use of some phthalates in cosmetics and other consumer products, in response to concerns about exposure as well as toxicity. In contrast, the Cosmetic Ingredient Review, a panel funded and advised by the cosmetic industry, determined that DMP is safe as used in cosmetics (CIR 2002).
Phthalates are potent toxins to the male reproductive system. One recent study found suggestive evidence that high levels of mMeP, the breakdown product of DMP, are associated with altered sperm morphology in adult men (Duty 2003). High levels of other phthalate metabolites are associated with reduced levels of sperm motility and concentration, and alterations in hormone levels in adult men (Duty 2003, 2004, 2005). A recent study of 134 births found marked differences in the reproductive systems of baby boys whose mothers had the highest measurements of other phthalate metabolites during pregnancy (Swan 2005). A second study indicates that these mothers' phthalate exposures were not extreme, but rather were typical for about one-quarter of all U.S. women (Marsee 2006). Further research documented decreased testosterone levels among baby boys exposed to mMeP in their mother's breast milk (Main 2006).
In addition to this epidemiological research on humans, laboratory studies indicate phthalates cause a broad range of birth defects and lifelong reproductive impairments in animals exposed in utero and shortly after birth (Marsman 1995; Wine 1997; Ema 1998; Mylchreest 1998, 1999, 2000; Gray 1999). Phthalate exposures damage the testes, prostate gland, epididymis, penis, and seminal vesicles in laboratory animals (Mylchreest 1998); most of these effects persist throughout the animal's life. DMP has not been as thoroughly studied as other phthalates, but existing studies show that it may cause liver toxicity (Field 1993). DMP does not appear to be as potent as other phthalates in causing male reproductive tract toxicity (Gray 2000).
Dimethyl phthalate
Used in insect repellant, plastic, rocket propellant. DMP is linked to liver toxicity, and its breakdown product is linked to male reproductive system problems in people.
Dimethyl phthalate has been found in 6 of the 9 people tested in EWG/Commonweal studies.
Top health concerns for Dimethyl phthalate (References)
| health concern or target organ | weight of evidence |
| Endocrine system | unknown |
Other health concerns for Dimethyl phthalate (References)
| health concern or target organ | weight of evidence |
| Gastrointestinal (including liver) | unknown |
Results for Dimethyl phthalate
in blood serum (lipid weight)
Showing results from EWG/Commonweal Study #1, industrial chemicals and pesticides in adults
EWG/Commonweal results
- found in 6 of 9 people in the group
Detailed toxicity classifications (References)
| classification | governing entity/references |
| Gastrointestinal system toxicity - weight of evidence unknown/unassessed | Field EA, Price CJ, Sleet RB, George JD, Marr MC, Myers CB, et al. 1993. Developmental toxicity evaluation of diethyl and dimethyl phthalate in rats. Teratology 48(1): 33-44. |
| Endocrine system toxicity - weight of evidence unknown/unassessed | Main KM, Mortensen GK, Kaleva MM, Boisen KA, Damgaard IN, Chellakooty M, et al. 2006. Human breast milk contamination with phthalates and alterations of endogenous reproductive hormones in infants three months of age. Environ Health Perspect 114(2): 270-276. |
| Gastrointestinal system toxicity - weight of evidence unknown/unassessed | Field EA, Price CJ, Sleet RB, George JD, Marr MC, Myers CB, et al. 1993. Developmental toxicity evaluation of diethyl and dimethyl phthalate in rats. Teratology 48(1): 33-44. |
