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Diethyl Phthalate

Medically reviewed by Last updated on May 19, 2023.

Excipient (pharmacologically inactive substance)

What is it?

Diethyl phthalate (C12H14O4), or DEP is a diethyl ester of phthalic acid. DEP is used as a plasticizer in consumer goods, including plastic packaging films, cosmetics, solvent for fragrances, a surface lubricant in food and pharmaceutical packaging, and in tubing used for medical purposes. It is a colorless, oily liquid.[1]

There are concerns about the toxicity of phthalates in consumer products and the environment. Exposure to DEP can occur through inhalation, ingestion, eye or skin contact. Some studies suggest little toxicity, but other research has identified reproductive toxicity in animal studies.[2]

According to a document published by the Centers for Disease Control and Prevention (CDC) for occupational safety, diethyl phthalate has irritant effects on the eyes, skin, and mucous membranes and can lead to central nervous system (CNS) effects in exposed workers. CNS effects only occurred in exposed workers after 6 to 7 years of chronic exposure to phthalates.[3]

List of medications using Diethyl Phthalate


  1. Chemical Information Profile for Diethyl Phthalate. National Toxicology Program National Institute of Environmental Health Sciences National Institutes of Health U.S. Department of Health and Human Services Research Triangle Park, NCNIH.
  2. Autian J. Toxicity and health threats of phthalate esters: review of the literature. Environmental Health Perspectives 1973. 4: 3–25. Accessed March 31, 2012.
  3. CDC. Occupational Health and Safety Guideline for Diethyl Phthalate.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.