3M began producing PFOA (the most infamous "forever chemical") in 1947. It has been widely used in industry, and many millions of pounds of the stuff have been dumped into waterways since then. PFOA manufacturers were aware of some of the negative health effects of the substance in lab animals in the 1960s. Researchers outside of corporate America began studying PFOA in the 1980s. In the early 2000s, PFOA exposure via drinking water began to get public attention due to a lawsuit against DuPont.
As far as I know, the US government had no recommended limit on PFOA exposure in drinking water between 1947 and 2009.
Since 2009, limits have become progressively stricter. (For the timeline below, I'm quoting https://www.nrdc.org/press-releases/epa-restricts-toxic-pfas... )
In 2009, EPA established provisional health advisories for PFOA at 400 ppt and for PFOS at 200 ppt.
In 2016, EPA set a lifetime health advisory of 70 ppt for PFOA and PFOS combined.
In 2022, EPA published interim lifetime health advisories of 0.004 ppt for PFOA and 0.02 ppt for PFOS.
In 2023, EPA proposed health-based maximum contaminant level goals (MCLGs) for PFOA and PFOS of 0 ppt.
A lot of these chemicals are newer and less well-studied than PFOA, and we may still be in the period where federal limits are hundreds or thousands of times higher than the true safe level.
So am I reading this right you're probably an order of magnitude below the 'safe' limit even if you subsist solely off of RXBars and Sweetgreen? Which is not so far from me at one point in my 30s...
I didn't expect to open this chart and feel _better_ about my plastic consumption, maybe I'm just misunderstanding the chart. It seems even if the limits are 10x too high, you're still probably fine.