chemical information
CAS RN:

2528-16-7

Chemical Class:

Phthalates

Found in these people:

Sara Corbett, Nicholas, May, Participant #1, Participant #10, Fred Gellert, Adelaide Gomer, Ann Hunter-Welborn, Jesse Johnson, Winsome McIntosh, Judi Shils, Participant #18, Lynde Uihlein, Participant #2, Participant #20, Jessica Welborn, Alicia Wittink, Irene Crowe, Martha Davis, Emily Sayrs, Participant #6, Annette Gellert, Heather Gellert, Landon Gellert, Anonymous Adult, Jessica Assaf, Erin Schrode, Asta Haman-Dicko, Hope Atkins, Rizza Alcaria, Alex Wells, Anonymous Teen 9, Anonymous Teen 20, Emma Spencer, Christa Heffron, Natalie Klapper, Sydney Blankers, Anonymous Teen 11, Sarah Oswald, Caroline Burlingame, Laurie Mittelmann, Monica Paulson, Linda Loi, Donalin Cazeau, Jenny Gilbertson, Anonymous Adult 2, Anonymous Adult 3, Anonymous Adult 5, Anonymous Adult 4, Anonymous Adult 6, Anonymous Adult 7, Anonymous Teen 1, Anonymous Adult 9, Anonymous Adult 12, Anonymous Adult 13, Anonymous Adult 11, Anonymous Adult 10, Anonymous Adult 14, Anonymous Adult 15, Anonymous Adult 16, Anonymous Adult 17, Anonymous Adult 18, Anonymous Adult 20, Anonymous Adult 21

Found in these locations:

NY, USA; CA, USA; Belvedere, CA; Ithaca, NY; Encinitas, CA; New York, NY; Washington, DC; Ross, CA; VA, USA; Milwaukee, WI; CO, USA; San Francisco, CA; Littleton, CO; MD, USA; San Rafael, CA; San Leandro, CA; Tuolumne, CA; Manteca, CA; Austin, TX; Winchester, MA; Portland, OR; Belmont, CA; Los Angeles, CA; Palm Beach Gardens, FL; Langhorne, PA; North Caldwell, NJ; University Place, WA; Dorchester, MA; Novato, CA; Chicago, IL; Newton, MA; Fredericksburg, VA; Lamont, FL; Atlanta, GA; Mountain View, CA; Stanford, CA; Palo Alto, CA; Berkeley, CA; Alamo, CA; Fallbrook, CA

Exposure routes:

Breakdown product of chemical used in cosmetics, paint, plastic, food packaging, and other common consumer products.


Summary

Found within many consumer products, phthalates are industrial plasticizers that impart flexibility and resilience to plastic, among other uses. Monobenzyl phthalate (mBzP) is a metabolite, or breakdown product, of butyl benzyl phthalate (BBzP), used in vinyl flooring, adhesives, sealants, stains, texture coatings, car-care products, and to a lesser extent, some personal care products (EWG 2003; Wolff 2007; CDC 2005). Exposure to butyl benzyl phthalate occurs through direct use of products containing this chemical, as well as through inhalation of contaminated air (CDC 2005).

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 mBzP is a widespread contaminant of the human body (CDC 2005). Measurements of mBzP 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 89 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.

Phthalates are potent toxins to the male reproductive system. High levels of mBzP 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 mBzP phthalate measurements during pregnancy (Swan 2005). A second study indicates that these mothers' 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 phthalates 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 (e.g., Mylchreest 1998); most of these effects persist throughout the animal's life. In addition, EPA considers BBzP to be a possible human carcinogen.

Further epidemiological studies indicate phthalates may produce non-reproductive health effects in people. Increased levels of mBzP were associated with increased waist circumference and insulin resistance in adult men in the United States (Stahlhut 2007). According to the American Heart Association (2007), over 60 million Americans have insulin resistance; 1 in 4 of these people develop Type 2 diabetes. In another study of 400 children, half with allergies, high levels of the mBzP parent compound BBzP in dust were associated with rhinitis and eczema (Bornehag 2004).




Monobenzyl phthalate

Breakdown product of benzylbutyl phthalate, used in vinyl flooring, car-care products, some cosmetics. Fetal and adult exposures are linked to male reproductive problems.

Monobenzyl phthalate has been found in 74 of the 74 people tested in EWG/Commonweal studies. It has also been found in 7,917 of the 8,020 people tested in CDC biomonitoring studies.


Other health concerns for Monobenzyl phthalate (References)

health concern or target organ weight of evidence
Chronic effects, generalunknown
Immune system (including sensitization and allergies)limited
Respiratory systemunknown


Results for Monobenzyl phthalate

in urine

Showing results from Dateline NBC Families, EWG Study #10, cosmetic chemicals in teens, EWG/Commonweal Study #7, consumer product chemicals in adults and teens, Dateline NBC Families, Pets Project, EWG Study #6, consumer product chemicals in mothers and daughters, EWG Study #8, chemicals in mother and 2 children

EWG/Commonweal results

  • geometric mean: 22.4 ug/g creatinine in urine
  • found in 74 of 74 people in the group

CDC biomonitoring results

  • geometric mean: 13.6 ug/g creatinine in urine
  • found in 7917 of 8020 people in the group
0.08 ug/g creatinine in urine 7400


Monobenzyl phthalate results


Detailed toxicity classifications (References)

classification governing entity/references
Chronic effects, general - weight of evidence unknown/unassessedStahlhut RW, van Wijngaarden E, Dye TD, Cook S, Swan SH. 2007. Concentrations of urinary phthalate metabolites are associated with increased waist circumference and insulin resistance in adult U.S. males. Environmental health perspectives 115(6): 876-882.
Limited evidence in humans - immune system toxicityBornehag C, Sundell J, Weschler CJ. The association between asthma and allergic symptoms in children and phthalates in house dust: a nested case-control study. Environmental Health Perspectives 112: 1393-1397 (2004).
Chronic effects, general - weight of evidence unknown/unassessedStahlhut RW, van Wijngaarden E, Dye TD, Cook S, Swan SH. 2007. Concentrations of urinary phthalate metabolites are associated with increased waist circumference and insulin resistance in adult U.S. males. Environmental health perspectives 115(6): 876-882.
Respiratory system toxicity - weight of evidence unknown/unassessedBornehag C, Sundell J, Weschler CJ. The association between asthma and allergic symptoms in children and phthalates in house dust: a nested case-control study. Environmental Health Perspectives 112: 1393-1397 (2004).