Silicone bakeware as source of human exposure to cyclic siloxanes | Hacker News Reader

Silicone bakeware as source of human exposure to cyclic siloxanes

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39 pointsshaggie7623 comments

Silicones are common food additives, including use as an anti-foaming agent in frying oil. If you are trying to avoid them, you may rethink having those fries next time you are at the drive through.

They are also used almost everywhere around us... shampoos, lotions, cleaning agents, cosmetics, medical implants, electronics, lubricants, etc. It seems a few ppm improves every kind of product.

What is the ppm emitted of siloxanes or silicone-equivalents from frying oil?

What is the ppm emitted rate from shampoos?

Simply declaring the presence of a contaminant in other goods is not a meaningful contribution here.

Is cyclic siloxanes the same as cyclosiloxane?

I thought silicone was recommended over plastics/nonstick/etc because it's inert and chemically simple. The wikipedia says that cyclosiloxane is volatile, often used as a solvent, and evaporates.

Since it declines over time, it doesn't seem to be the result of normal wear/tear of the bakeware which does suggest it's something added during the manufacturing process. I've heard of doing an initial bake of silicone bakeware to remove factory stuff...

So is silicone as a cooking material actually fairly complex, new, and not as well understood as I thought (similar to plastics)? Or is this an avoidable manufacturing thing.

Also they mention "concerns", but I couldn't find any known health risks. Is this similar to microplastics, where it could be an issue but it isn't clear yet? Or are they known to be harmful?

I'm no chemist.

They were nice enough to provide repeat experiments in 3.5, figure 2. It shows the release of c-siloxane drops of dramatically after the first baking. Then it tapers off.

That suggests to me this is not a structural component, but a solvent, softener, coating or similar that sits between the structural silicone. Otherwise, I'd expect reports of the silicone molds degrading after baking. Though I guess it could be material that simply didn't mate with a polymer chain. But that doesn't jive with the (sparse) Wikipedia article [1].

This doesn't say anything about whether they are inert. If they are inert and not meant to be bound to anything, then it makes sense they'll be washed away, and that doesn't matter (in the PFAS sense, where it turns out it does eventually matter :).

The EU is looking at D4-6 because it's bioaccumulative. Canada (where this study is from) looks at D4 [2].

Overall, this looks like a very comprehensive study. Many aspects covered. I'd like to also complain that mixing "cyclic siloxane" with "c-siloxane" makes it much more difficult to search through the paper. Why not stick with one name?

[1] https://en.wikipedia.org/wiki/Cyclosiloxane

[2] https://en.wikipedia.org/wiki/Siloxane#Safety_and_environmen...

> Repeated baking shows a steady decline in migration and emissions, suggesting depletion of siloxanes in the products over time.

I wonder what the fall-off curve looks like for siloxane transfer out of the bakeware. If e.g. 70% of it comes out in the first 15 baking cycles, there could be a reasonable path to massively reducing exposure from this source. Just cook a few sacrificial recipes on new bakeware and throw them out uneaten.

This wouldn't even need to be done.

Initial wear cycles could be simulated prior to shipment.

We've been using random unbranded silicone cookware and parchment paper with air fryer. Should we switch?

I use a ninja crispi these days. It's incredibly easy to clean. The food goes directly on the glass. I threw away their plastic tray thing the moment I found it in the packaging.

Most parchment paper (baking paper) is silicone-coated as well, no?

PFAS coated. Many products including floss, contact lenses, tampons, weatherproof gear also.

"In February 2024, the FDA announced that substances containing PFAS used as grease-proofing agents on paper and paperboard for food contact use are no longer being sold by manufacturers into the U.S. market." [0]

[0] https://www.fda.gov/food/process-contaminants-food/authorize...

They could be sitting on ten years of supply.

We learned around 2020 that wasn't the case.

Did we? 2020 data is useless and irrelevant anyway since the governmental efforts to stop its production came later, corresponding with industry efforts to bulk up its production before the governmental pressure took effect.

A fascinating display of confidence unburdened by evidence. Basically the intellectual equivalent of arguing that gravity “probably took a few years to kick in.”

Are you actually saying that companies were predicting government regulation years in advance and preemptively cranking out bulk PFAS-coated paper just in case? Because, of course, that’s what every industry does: mass-produce soon-to-be-banned chemicals for fun and profit.

If you use an air fryer oven, not a regular air fryer, you no longer need parchment paper except if heating very small items. You can use aluminum foil just fine if really needed.

Just season some carbon steel baking pans. The seasoning is non-stick like coating. And works well enough for most things in my experience.

And carcinogenic as fuck. "Seasoning" is basically plastic made from burnt oil with constituents including acrylamides.

Why not cook on less toxic surfaces that are clean?

Acrylimides do not apear to be likely to acumulate on iron cookware, and types that may be formed in food, are not concidered probimatic. https://en.wikipedia.org/wiki/Acrylamides

If your worried about acrylamides then you should not be browning any starchy foods. A lot cooking intentionally wants the Maillard reaction for flavor and texture reasons.

When it comes to seasoning carbon steel you should not be letting carbon build up. It's a bad habit. If your getting carbon build up clean it off with something coarse like salt or a metal scrubber. After that if you need to it's not hard to give a pan a quick touch up seasoning with oil. Carbon steel is much quick to touch up season than something like cast iron. Cast irons rough sand cast surface means you generally need a much much thicker seasoning layer.

You also should still clean the pan too! Modern dish washing detergents are generally not made from lye so won't strip your seasoning.

You can smooth out a cast iron cook surface. It only tales a few seconds with a flapper wheel on an angle grinder.

Wish I'd thought of that; I spent a couple hours at it using an orbital sander, up to 320 grit. No regrets though, that pan is easily my favorite piece of cook ware.

What effects does exposure have?

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