This might be true at the very low end of the market, but most sunscreen brands that people care about enough to have loyalty are uniquely sourced products.
They aren't using benzene intentionally as an ingredient. So even if they aren't just reselling a generic product this is likely an impurity in one of the ingredients. It doesn't really matter if its a white label or if its custom manufactured for the big brand. In the end it could still vary next month if the source materials are not sufficiently controlled. Although it could be the same if the process results in consistent levels of impurities.
Does expiration date reflect a difference in manufacturing date? For the listed affected products between .1ppm & 2ppm Benzene, Expiration dates range from July 2021 to May 2023.
Not if they're all getting a key component from the same supplier. Every niche brand and even someone like CVS isn't going to run it's own chemical refineries for each ingredient in the sunscreen. They're going to use a relatively small group of suppliers. It only takes one of them selling to dozens of manufacturers to taint both mainstream and obscure brands.
QA can be a big differentiator between competing companies that share upstream suppliers. It could be that one sunscreen maker is testing for crap/contaminated precursors and another isn't.
Good point. The difference between quality products sometimes just comes down to specified mechanical tolerances and purity levels of chemicals/ingredients. Though price usually increases much faster than quality at higher levels. Going from 95% to 97% pure might cost $X, but 97% to 99% will be $X * 5.
