Silicone, cure not stated

What it is

This label means a part is silicone rubber, and the maker hasn't said how it was cured or which food-contact standard it meets. That's common, and one email to the maker usually settles it.

Why it matters in your kitchen

Silicone can be cured with a platinum catalyst or with a peroxide. Silicone makers sell food-contact grades meant to meet FDA's rule for rubber articles or Germany's BfR recommendation, once properly cured and post-cured.

"Silicone" alone doesn't tell you which you have. Most of the time it's a gasket or seal: small, out of sight, and touching your food when the container tips.

Good at

• Sealing. Whatever the cure, silicone flexes into a lid groove and keeps a seal.
• Easy to swap. Many makers sell spare gaskets.
• Honest labeling. We'd rather mark the gap than guess at it.

Watch for

• The cure is unknown. Ask the maker whether it's platinum or peroxide cured.
• The standard is unknown. Ask whether the part meets FDA 21 CFR 177.2600 or the BfR silicone recommendation.
• Gaskets trap water. Take it out to wash, and let it dry before reassembling.
• It's still a polymer. A product with a silicone seal isn't plastic-free in the strict sense.

Who it suits

Fine for most people as a small seal. Skip it if you want every food-contact part documented, and pick a product that names the cure and standard.

In short. "Silicone, cure not stated" means the part is silicone and the maker hasn't documented how it was cured or which food-contact rule it meets.

Compare platinum-cured silicone. For what research has and hasn't shown about kitchen materials, see our guide.

Where it is used

• Gaskets, lids and seals

How to care for it

• Same care as any silicone part: remove it to wash, dry it, replace it when it tears or stops sealing.