Not to mention Hanlon’s razor

Holy shit, Swiss Francs are portrait. That’s mad.

This is such a pointless thing to take umbrage with. Looking at the table showing the levels and picking one of the highest ones from a brand I’ve heard of: Colgate Total Whitening comes in at 539 ppb of lead. We’ll call that 0.539 ppm to make the maths slightly easier, because that’s equivalent to μg/g.

Let’s say you really load up your toothbrush and use 2ml instead of a pea-sized blob, and assuming a specific gravity of 1.30, that’s 2.6g of toothpaste, of which 0.539 μg/g is lead. So you would ingest 2.6g × 0.539μg/g = 1.3936μg of lead if you swallowed all of that toothpaste every time you brushed your teeth.

Apparently young children swallow 0.053-0.3g of toothpaste, so let’s go roughly in the middle and say you swallow 0.18g, so 0.18 × 0.539 = 0.097μg of lead. Call that 0.1μg and you brush twice a day, so 0.2μg of lead per day from brushing your teeth. If you use a pea-sized amount, then halve that to 0.1μg.

The EPA’s maximum allowable limit of lead in drinking water is 15ppb, but is lowering to 10ppb (ppb = μg/litre) in 2027. So let’s say you live somewhere well below that limit and it’s 5ppb in your area. You’re supposed to drink 1.5 to 2 litres of water a day, so at 5μg/litre that’s 7.5 to 10μg of lead per day from drinking water, or 75 to 100 times more than the amount from brushing your teeth.

My bank immediately referred themselves to the financial ombudsman (UK) when they realised they’d been charging me for an account they weren’t supposed to be, which I was very mildly impressed by.