Large O ring on dizzy? Rubber or other

I guess someone could run a test, soaking the Harbor Freight "viton" and "nitrile" O-rings in gasoline for a month. Seems I recall seeing where someone did that. I doubt they misrepresent the product and most HF products I bought have served well and most I would never have bought at Snap-on prices. Re Chinese, I bought 1/8" viton tubing for my M-B diesel injector return hoses off ebay. It has held up fine for over a year and I use bio-diesel (Propel HPR) which is more aggressive. It seems to truly be viton since everyone who has tried regular black vacuum hose (nitrile) found it swells in a week, even w/ regular diesel, and I saw that when I tried a little silicone hose "just to verify".