It is used as a quantitative stain for histones at alkaline pH after acid extraction of DNA.
Fast Green FCF is poorly absorbed by the intestines.
[2] Its use as a food dye is prohibited in the European Union and some other countries.
In the United States, Fast Green FCF is the least used of the seven main FDA approved dyes.
A reevaluation of Fast Green FCF published by the World Health Organization in 2017 concluded that it has low toxicity and is not carcinogenic or genotoxic, and that there were no health concerns with consumption of Fast Green FCF at the previously established allowable daily intake (which itself is much higher than estimates of actual dietary exposure to Fast Green FCF).