Interesting that the regulations are done that way in terms of both an average and a maximum. I wonder how the average is determined, how many samples, and what

Interesting that the regulations are done that way in terms of both an average and a maximum. I wonder how the average is determined, how many samples, and what is the size of a batch etc.? > 18% of gasoline’s weight is the BTEX aromatics, benzene, toluene, ethylene-benzene, and xylene. https://www.fuelfreedom.org/is-there-a-better-gasoline-addit https://www.fuelfreedom.org/is-there-a-better-gasoline-addit.... > This may be done depending on the season to increase the octane of gasoline. > An average of 18% of these aromatics is not what I’d call just trace amounts… Yes, BTEX is added to improve octane. It's also possible to increase octane by alkylation and isomerization, which produce branched alkanes which tend to be less toxic and burn cleaner than aromatics, but reformation/dehydrogenation which produces aromatics is cheaper.. But yes, while the other aromatics aren't exactly healthy, they're nowhere as dangerous as benzene. So it makes sense to minimize the amount of benzene via regulation, but be a bit less strict about the other aromatics. As an aside, a quick glance on that "fuelfreedom.org" site suggests they really like ethanol as a fuel additive, which makes me suspect they might be a front group for the corn ethanol lobby. So I'd be wary of taking what they say at face value.