It received critical attention from environmental safety activists[2][3] because of the toxicity concerns of 2-butoxyethanol (EGBE), which was in the formula at under 4%.
[4] As of 2013, 2-butoxyethanol has been removed from Simple Green all-purpose cleaner, so now it has an NFPA/HMIS rating of 0/minimal for Health, Fire, Reactivity, and Special.
Simple Green has been re-listed as an approved Surface Washing Agent per the EPA's National Contingency Plan after being de-listed in 1995.
[7] In 2001, Crystal Simple Green was used to clean up an oil spill in the Baltic Sea.
Crystal Simple Green combined with crude oil #2 did not affect adults but did increase the mortality rate of fry to 46%.