this post was submitted on 23 Mar 2026
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Mildly Interesting

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I've never seen labeling like this before. Interesting.

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[–] Jessica@discuss.tchncs.de -1 points 3 days ago* (last edited 3 days ago) (6 children)

I have bad news about the first ingredient, calcium carbonate. ~~It contains lead!~~

Edited for clarity: it is derived from chalk as the toothpaste explains and effectively all chalk on Earth is contaminated with lead as shown in the article below, which uses x-ray fluorescence to confirm the presence of lead, cadmium, mercury, arsenic.

In general, you want to avoid the following ingredients in your toothpaste if you are trying to minimize lead exposure:

  • Bentonite Clay
  • Hydroxyapatite 
  • Calcium Carbonate
  • Hydrated Silica
  • Titanium Dioxide

https://tamararubin.com/2025/01/toothpaste-chart/

[–] Lumisal@lemmy.world 10 points 3 days ago

I question their methods if they're also afraid of fluoride

[–] grue@lemmy.world 8 points 3 days ago* (last edited 3 days ago) (1 children)

More like "the chalk the calcium carbonate comes from is contaminated with lead," interpreting your claim as charitably as possible. Calcium carbonate is the specific chemical compound CaCO~3~; if Pb is present it's a different compound entirely.

Moreover, I highly doubt that every possible commercial source of chalk is contaminated with lead, so unless you can tell which specific product this is just from the picture and know that it's been tested by that site, you can't make that claim in the absolute language you used.

And even then, that's assuming the site itself is credible.

[–] Jessica@discuss.tchncs.de 2 points 3 days ago* (last edited 3 days ago)

Yeah that's pretty much exactly what I'm saying. I just didn't really feel like typing it all out. Yes the claim there is effectively all chalk is contaminated with lead based on all of the different XRF results she's done on toothpaste.

Kind of like how basically all cocoa beans are contaminated with lead and cadmium as shown by consumer reports. The beans themselves do not contain lead, but the countries that harvest the beans just throw them on the ground and the ground is contaminated with lead and the dust gets on the beans and makes its way into our dark chocolate.

[–] la508@lemmy.world 2 points 2 days ago (1 children)

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.

[–] Jessica@discuss.tchncs.de 1 points 2 days ago

Thank you very much for doing the math! That really does put it into perspective.

I was assuming you would still be absorbing the lead through your gum line and sublingually through the glands under your tongue into your bloodstream even without swallowing any, but that does sound like extremely low quantities.

For me personally, I have ADHD and a bad memory so anything I can do to mitigate exposure to lead to lessen my chance of developing Alzheimer's or Dementia as I get older seemed like an obvious decision especially when the solution is to just get a low abrasion toothpaste that doesn't include these potentially contaminated abrasive materials.

[–] AmidFuror@fedia.io 5 points 3 days ago (1 children)

Tums and similar antacids are almost entirely calcium carbonate. According to their website:

The active ingredient in TUMS is calcium carbonate from a mined calcium source. It may be an appropriate option for people who cannot consume calcium sourced from shellfish. Each tablet contains 1000 mg of calcium carbonate, 410 mg of elemental calcium, 5 mg of magnesium and 2 mg of sodium.

Mined and from shellfish sounds like chalk to me.

Sure enough, in their FAQ:

The calcium carbonate in TUMS antacid is processed from pure limestone, resulting in a high degree of purity.

Let's compare toothpaste, which one uses a small amount of twice a day and consumes (if old enough) almost nothing to an antacid made for occasional use but consumed in hundreds to thousands of milligrams at a time. Seems like there should be far more consumer concern about lead in antacids.

I found a paper about determining limits of lead detection in CaCO3, but they spiked lead into antacid tablets. There doesn't seem to be a whole lot of concern out there about all this lead in chalk.

[–] Jessica@discuss.tchncs.de 1 points 3 days ago

For what it's worth, the toothpastes that only used calcium carbonate had quite low levels of lead. It seemed to be the ones that use bentonite clay that have ridiculously high levels of lead and that is the far more concerning ingredient which was not present in OP's photo

[–] mrgoosmoos@lemmy.ca 4 points 3 days ago (1 children)

this is a joke, right?

how would anybody take that website seriously? it screams "hit back, never return, and forget I exist"

[–] SlurpingPus@lemmy.world 1 points 3 days ago (1 children)

Weird kneejerk. What specifically is wrong with their methods of research?

[–] mrgoosmoos@lemmy.ca 0 points 3 days ago (1 children)

I'm not talking about their methods. I'm talking about the presentation.

[–] SlurpingPus@lemmy.world 0 points 3 days ago (2 children)

Ah, indeed, that's certainly the correct approach to any scientific info.

[–] ratsnake@lemmy.blahaj.zone 2 points 3 days ago (1 children)

"Is it in a serious, reliable publication" is indeed a good first question to ask yourself when trying to determine if something is scientific information or just some rando's personal opinion.

[–] SlurpingPus@lemmy.world 1 points 3 days ago

Just to check, you definitely use the same criterion when you read about a dude measuring stuff with a multimeter, right?

[–] mrgoosmoos@lemmy.ca 0 points 3 days ago (1 children)

uh, yes? do you seriously think presentation is not a part of it?

[–] SlurpingPus@lemmy.world 0 points 3 days ago (1 children)

Explain to me how the presentation affects whether there's lead in toothpaste.

[–] mrgoosmoos@lemmy.ca 0 points 2 days ago (1 children)

oh, you're just intentionally playing stupid. got it.

[–] SlurpingPus@lemmy.world 1 points 2 days ago* (last edited 2 days ago)

Looks more like you're playing stupid, but you might simply be sincere, who knows.

[–] ayyy@sh.itjust.works 2 points 3 days ago (1 children)

LEAD SAFE MAMMA LLC AMAZON AFFILIATE LINK……..nah I’m good. You’re being scammed.

[–] Jessica@discuss.tchncs.de 2 points 3 days ago* (last edited 3 days ago)

You probably aren't aware, but x-ray fluorescence guns cost like $20,000 so I can understand why she would have an Amazon affiliate link