Analysis / 17α-Ethinylestradiol (EE2)

PharmaceuticalsC₂₀H₂₄O₂CAS 57-63-6

17α-Ethinylestradiol (EE2)

Cities measured

87

Detected in

87 / 87

Highest

0.0014 μg/L — Beirut

Overview

EE2 is the active estrogen in combined oral contraceptives. It is synthetic, far more resistant to environmental degradation than natural estrogens, and excreted partially unchanged. Over 100 million women worldwide use EE2-containing contraceptives.

Health Relevance

EE2 feminises fish at 4–6 ng/L — including complete sex reversal. Because it is synthetic and non-biodegradable, it persists longer and accumulates more than natural estrogens.

Regulatory Limits

EU

Drinking Water Directive 2020/2184

No EU drinking water limit. Proposed EU Environmental Quality Standard (EQS) of 0.035 ng/L for surface water (under Priority Substances Directive) — never formally adopted.

Controversy & Contested Science

The proposed EQS of 0.035 ng/L triggered intense controversy in 2012. Meeting it would require membrane bioreactor or ozone treatment at all urban wastewater plants — estimated cost €5–20 billion across the EU. The Commission excluded EE2 from the Priority Substances list in 2013 — widely criticised as a decision driven by lobbying rather than science. Environmental law NGOs challenged the exclusion at the European Court of Justice. The controversy remains unresolved, and EE2 continues to be discharged into EU surface waters without regulatory limit.