Malachite Green - Toxicity

Toxicity

The LD₅₀ (oral, mouse) is 80 mg/kg. Rats fed malachite green experience “a dose-related increase in liver DNA adducts” along with lung adenomas. Leuco-malachite green causes an “increase in the number and severity of changes”. As leuco-malachite green is the primary metabolite of malachite green and is retained in fish muscle much longer, most intake of malachite green would be in the leuco form. During the experiment, rats were fed up to 543 ppm of leuco-malachite green, an extreme amount compared to the average 5 ppb discovered in fish. After a period of two years, an increase in lung adenomas in male rats was discovered but no incidences of liver tumors. Therefore it could be concluded that malachite green caused carcinogenic symptoms, but a direct link between malachite green and liver tumor was not established.