[jacobgold]

You shouldn't use aluminum foil with tomato/lemon/vinegar/brined foods or as "grilling packets" (direct fire/high heat) because of leaching risk.

There's no concern with using aluminum in most cases (with dry/non-acidic foods) but leaching is a real problem with acidic/salty/wet/high eat.

[kragen]

Let's see if this is a quantitatively plausible concern.

https://en.wikipedia.org/wiki/Aluminium_chloride says orl-rat LD₅₀ of AlCl₃ is 380mg/kg, which is 20.2% aluminum by weight, so that's 77mg/kg of soluble aluminum ions. If this toxicity is due to soluble aluminum ions (rather than, say, acidity), and rats and humans are about equally sensitive to aluminum toxicity, you'd need about 3.8g of aluminum to kill a 50kg human, the ionized equivalent of 1.42mℓ of aluminum metal (at 2.71g/cc). That's 1420cm² of 10μm aluminum foil completely dissolved in the food.

Presumably you would get significant toxic effects well before reaching the lethal dose, so it would be wise to avoid exposures larger than a few tens of cm² of aluminum foil completely dissolved in your food. So it seems like the concern at least passes the first smoke test of plausibility: the total amount of aluminum present in a "grilling packet" is at least sufficient to worry about.

(Fortunately, aluminum rapidly becomes inert in the body, so we don't have to be concerned about gradual poisoning the way we do with lead and arsenic.)

The crucial question, then, is how fast the foil corrodes under cooking conditions! If it corrodes (and migrates into the food) at a micron or more per hour, then this could be a serious concern. But, if the corrosion rate is more like microns per month or microns per year, the dose wouldn't be high enough to worry about.

The fact that https://en.wikipedia.org/wiki/Aluminium_toxicity redirects to https://en.wikipedia.org/wiki/Aluminium_toxicity_in_people_o... suggests that this is at least not a recognized concern.

[Bender]

How long does it take to leave the body?

[kragen]

I'm not sure, but I think that normally it reacts with phosphate ions to form aluminum phosphate rather than leaving the body.

[burnte]

There's no risk to leeching, there's no data proving any link at all between Aluminum and Alzheimer's. I was a huge advocate for staying away from Aluminum cooking stuff for a long time and my mother even wound up with Alzheimer's. Simply put, I was wrong, there's no link.

[jacobgold]

> "There's no risk to leeching, there's no data proving any link at all between Aluminum and Alzheimer's."

EFSA (European Food Safety Authority) says acidic or salty foods can increase aluminum leaching from pans and foil into food: https://efsa.onlinelibrary.wiley.com/doi/pdf/10.2903/j.efsa....

This review found mixed evidence and a positive meta-analysis signal for aluminum exposure and Alzheimer's: https://www.sciencedirect.com/science/article/pii/S014765132...

It's not that hard to avoid this leaching concern, seems smart to make a basic effort to do so.

[Nifty3929]

"Aluminum (Al) is a widespread environmental contaminant " - they lost me right there in the very first sentence.

Already using charged, non-neutral language ("contaminant"), giving away their pre-existing bias and forcing me to disregard the rest of their opinion on the matter. Aluminum is no more "environmental contaminant" than any other extremely common basic element in the Earth's crust, like silicon or iron. Are they also against chlorine?

Clearly they decided to conduct a study to show just how scary aluminum is, and I have no doubt the succeeded.

[burnte]

Yeah, it's the third most abundant element on the planet. If that's a contaminant, then so is iron and oxygen and nitrogen. Did you know Dihydrogen Monoxide is found in 100% of cancers?

[jacobgold]

This is a paper on ecotoxicology and environmental safety, so describing aluminum as an "environmental contaminant" makes sense in this context.

> "Did you know Dihydrogen Monoxide is found in 100% of cancers?"

Did you know humans intentionally consume water because they need it to survive, and do not intentionally consume aluminum?

[burnte]

The EU is known to be far more conservative with health and safety than other areas. I focused on the risk of aluminum, not leeching because leeching doesn't matter of the aluminum doesn't cause any issues. And from what I'ce seen in the past decade, it doesn't. I was wrong.

[badc0ffee]

What is the leaching risk, though? If aluminum does get in your food, is it bad for you in a specific way, or is it more like iron?

[a_conservative]

Aluminum is generally thought to be benign by most authorities.

However, it is worth noting that humans were not exposed to aluminum in the environment until relatively recently, when we started extracting it from bauxite and melting it.

[kragen]

Aluminum is a major component of all soils, and soluble aluminum salts have been used in medicine and dyeing since ancient Greece, probably since ancient Egypt. They have been used in food preparation for at least several centuries.

[shmeeed]

These are all separate chemical compounds, though. Are you claiming they all behave the same as refined aluminium?

I'll readily sprinkle soluble sodium chloride salt over my food. I still very much prefer to keep both substances away from it in elemental form.

Note that I'm not claiming aluminium were dangerous, just that your argument is deeply flawed.

[kragen]

It's not that my argument is flawed so much as that it depends on some basic background knowledge about processes like corrosion and solvation. Lacking that knowledge, you're better off taking my word for it that humans are not exposed to aluminum in the environment in a different way since we started refining the metal.

[IsTom]

Pure aluminium maybe not, but it's a major component of clay.

[jacobgold]

Like most metals, excess aluminum in your diet is almost certainly bad for you.

EFSA full review: animal studies show nervous-system effects from aluminum exposure. https://efsa.onlinelibrary.wiley.com/doi/pdf/10.2903/j.efsa....

CDC/ATSDR: oral risk levels are based on neurological effects seen in exposed animals. https://wwwn.cdc.gov/TSP/ToxProfiles/ToxProfiles.aspx?id=191...

[Perz1val]

I put aluminium foil over a bowl of pizza dough, as it grew the top touched the foil and in a few spots tiny holes appeared in the foil. I wonder if it was carbonic acid or what

[manwe150]

It probably formed a weak battery electrode with the bowl and electro-deposited it on the substrate (pizza). Happens often with tomato sauces, like lasagnas.

[kragen]

Oh, thanks! You are surely correct; I was puzzled about how something as relatively inert as pizza dough could corrode aluminum at multiple microns per hour, but electrolysis can definitely do that.