N-Acetyl (2-Cyanoethyl) Cysteine Test

N-Acetyl (2-cyanoethyl) cysteine is a mercapturic acid formed after exposure to acrylonitrile, a chemical used in the production of acrylic fibers, plastics, resins, and synthetic rubber. Common sources include cigarette smoke, indoor air from synthetic materials, and leaching from plastic food containers. Inhalation is the primary route of exposure, though ingestion and skin contact also occur.

Acrylonitrile is classified as a probable human carcinogen and is known to affect the respiratory, nervous, and cardiovascular systems. Acute exposure can cause dizziness, shortness of breath, and weakness, while chronic exposure has been linked to headaches, fatigue, and increased cancer risk, particularly lung cancer. These effects arise in part from acrylonitrile’s ability to interfere with cellular respiration and oxidative balance.

Metabolically, acrylonitrile is detoxified through conjugation with glutathione, forming N-Acetyl (2-cyanoethyl) cysteine for urinary excretion. Elevated levels may signal increased oxidative stress or depletion of glutathione, which is central to cellular defense against toxins. This makes the marker relevant not only for exposure assessment but also for evaluating detoxification burden.

That said, values may be influenced by smoking status and indoor air quality. Interpretation benefits from considering lifestyle and environmental factors alongside other volatile organic compound markers.