Is Silicone Safer Than Plastic? Plus 6 More Dow Corning Questions I've Learned the Hard Way

I'm a materials specifier at a mid-sized fabrication company. I've been handling silicone material orders for 9 years, and I've personally made and documented 11 significant mistakes, totaling roughly $38,000 in wasted budget. Now I maintain our team's checklist. This FAQ is the list I wish I had before those orders.

People ask me the same seven questions again and again:

• Is silicone safer than plastic?
• What does the Dow Corning name actually mean?
• Can I put Dow Corning AllGuard silicone elastomeric coating on extruded polystyrene insulation?
• Are Michaels silicone molds food-safe?
• What's the difference between silicone and rubber compound?
• Why did my silicone coating fail?
• How do I choose quality silicone without overpaying?

Is silicone safer than plastic?

Short answer: for food contact and high-temperature uses, I'd say silicone is generally safer than most plastics. It doesn't rely on the same plasticizers, and it can handle higher temperatures without melting or getting that weird chemical smell. The word 'safer' only means something when you know the application.

Most buyers focus on labels like BPA-free and completely miss the formulation. Food-contact silicone is usually platinum-cured and should meet US FDA 21 CFR 177.2600. Cheap or peroxide-cured silicone can contain byproducts that are less benign, especially at high heat. If a company calls a product eco-friendly, the FTC Green Guides (ftc.gov) say that claim needs to be substantiated. I've learned to ask for a test report rather than trusting the package.

What does the Dow Corning name actually mean?

Dow Corning is one of the oldest and most documented silicone brands, and it's now part of Dow's silicone business. When a spec calls for 'Dow Corning,' it's not a single material. There are sealants, greases, elastomers, emulsions, coatings, medical dispersions, and encapsulants under that name.

The reason brand matters to me is documentation. Off-brand silicone can look identical in the tube and still vary from lot to lot. With Dow Corning products, I can usually get a datasheet, lot traceability, and someone on the phone who understands the application. That's what I'm really paying for.

It took me six years and about 120 purchasing cycles to understand that a material spec is not a commodity part number. The cheapest option only looks cheap if you ignore testing time, failed parts, and customer headaches.

Can I put Dow Corning AllGuard silicone elastomeric coating on extruded polystyrene insulation?

When someone says 'Dow Corning extruded polystyrene insulation,' they usually mean an AllGuard coating applied over XPS, not that Dow Corning makes insulation. Dow Corning makes the coating, and AllGuard silicone elastomeric coating is designed for exterior insulation systems, including extruded polystyrene (XPS) and expanded polystyrene (EPS) foam.

But 'designed for XPS' doesn't mean 'zero prep.' I learned this in September 2022. We applied AllGuard to a dusty, weathered XPS panel and skipped the cleaning step because we were behind schedule. It looked fine for two weeks, then blistered near the cut edges. The coating wasn't at fault; my process was.

Now the checklist includes clean surface, patch damaged foam, prime cut edges if required, verify temperature, and do a small test patch before committing to the full wall.

Are Michaels silicone molds food-safe?

I've bought silicone molds at Michaels for craft projects, and many are labeled food-safe. But 'silicone mold' covers a lot. The same mold that works for resin or soap might not be intended for baking. If you plan to use it with food, the label should say food-safe, FDA-compliant, or platinum-cured.

The bigger red flag is smell. I once bought a cheap mold that smelled like chemical plastic at room temperature, checked the package, saw no food-safety mark, and returned it. That's not overreacting. Quality silicone does not smell like a new shower curtain.

If you're using the mold for resin craft, worry more about the resin than the mold. Wear gloves, ventilate the room, and follow the resin instructions. The mold isn't your biggest exposure.

What's the difference between silicone and rubber compound?

A rubber compound is any elastomer formulated from a base polymer like natural rubber, EPDM, nitrile, or neoprene, plus fillers and curing agents. Silicone is a synthetic elastomer with a silicon-oxygen backbone. Both feel rubbery, but their strengths are different.

Silicone handles high and low temperatures well, resists water, and stays flexible over time. A good rubber compound often has better tear strength and can be significantly cheaper. So one isn't automatically better.

It's tempting to think you can swap silicone for rubber compound and be done. I once did that on a high-temperature gasket to save money, and the test results came back with the exact opposite of what I wanted. The application decides the material, not the word 'rubber.'

Why did my silicone coating fail?

Most coating failures I've seen are from surface prep, film thickness, or cure conditions, not from the chemistry. In 2020 I approved a large exterior coating job without checking the substrate temperature. The coating cured too fast in direct sun and looked like a cracked desert floor within a month. That was my mistake, not a materials failure.

After the third coating rejection in Q1 2024, I created the pre-check list I still use. It covers cleaning, priming, mixing, temperature, and recoat windows. In the past 18 months it has caught 39 potential problems before they became expensive callbacks. That's the kind of return you don't see on a price comparison.

How do I choose quality silicone without overpaying?

Start with the datasheet, not the price. Look for tensile strength, elongation, durometer hardness, temperature range, and any certifications required for the application. Ask the supplier to put product numbers and certifications in writing.

I used to compare only price per gallon or per pound. That misses the hidden cost of failure. When we switched from budget silicone to a documented product, client feedback improved not because clients saw the brand name, but because things stopped failing. The $50 difference per project translated to noticeably better client retention.

Bottom line: buy material that has test data proving it works for your use case. If that's a Dow Corning product, great. If another brand has equivalent documentation, that's fine too. Just don't buy generic silicone and assume it's the same.