Profluralin is a dinitroanilineherbicide used preëmergently to control annual grasses and broadleaf weeds, in cotton, soybeans, peanuts, sunflower, cabbage, cauliflower, tomato and others.[4] Profluralin has largely fallen out of use.[3] It rose out of the related, still in common use, trifluralin.[5]
It was sold under the tradenames "Pregard" and "Tolban" (Syngenta),[3] registered in August 1975 and expiring in April 1984. Tolban was a 45% profluralin emulsifiable concentrate.[6] 48,000 pounds (22 t) was used in the US in 1974.[7] The USGS estimates that 5 to 65 thousand pounds (2.3 to 29.5 t) was used in 1994, with no usage after.[8]
Environmental decomposition by microörganisms happens in soil and water. Typical soil half-lives for profluralin are 80-160 days. Profluralin is adsorbed into plantmatter, so there is potential that it stay in crops after harvest. It is practically non-toxic to birds and mammals, though bees and fish are affected. If applied in high doses to rats, they may exhibit ataxia, slower breathing, salivation, prostration, hyperactivity or dyspnea. It interacts with dsDNA via electrostatic binding.[4]
Microörganisms in sewage cometabolise profluralin, trifluralin, fluchloralin and nitrofen; i.e. enzymes from other active metabolic processes also break up these chemicals. Over 88 days, profluralin levels reduced by 87% under aerobic conditions, into 9 metabolite products. Discontinuous anaerobic conditions slowed the process to a 23% reduction in the same time, with 5 metabolites.[10]
Safety
Profluralin is not toxic, not considered a carcinogen. Human harm is not expected, outside of eye irritation. Profluralin is very toxic to fish though, and is theorised to bioaccumulate in them.[1]
