When cooking or heating food, tableware and molds are usually made of plastic, silicone or rubber. But have you ever wondered which material is safest in high temperatures — such as microwave heating or boiling water — and which may release toxins? In this straightforward test, we compare the three under real cooking conditions to give you a clear answer. Test conditions Samples of plastic, ordinary rubber and liquid silicone were:

• Boiled in 100°C water for 30 minutes
• Heated in a 200°C oven for 15 minutes We observed deformation, discoloration, stickiness and odor to judge safety.

1. Plastic (general food‑grade, not high‑heat specialty)

• After 5 minutes in boiling water: began to soften and deform slightly
• After 30 minutes: obvious warping + faint plastic smell
• In 200°C oven (10 min): yellowed, sticky, partially melted, strong irritating plastic odor

Conclusion: Ordinary plastic cannot withstand high heat. It deforms and releases harmful substances, posing health risks with long‑term food contact.

2. Ordinary rubber

• After 10 minutes boiling: shrank, hardened, strong rubber odor
• After 30 minutes: surface cracking, worse smell
• In oven (<5 min): aged, brittle, crumbled easily, released harmful fumes

Conclusion: Poor heat resistance, easy to age, extremely unsafe at high temperatures — not suitable for hot food.

3. Liquid silicone

After both boiling and 200°C oven heating:

• No deformation, yellowing or stickiness
• No odor released
• Remained soft, elastic and almost unchanged
• No harmful substances released, fully compliant with food‑grade standards

Conclusion: Extremely stable and non‑toxic even under long‑term high heat.

Final Verdict

Under high temperatures:

• Plastic → deforms & releases toxins
• Rubber → ages & smells toxic
• Liquid silicone → safe, stable and non‑toxic

That’s why baby pacifiers, feeding tableware, baking molds and pressure cooker gaskets all prefer liquid silicone. ⚠️ Important note: Not all silicone is heat‑resistant. Only qualified liquid silicone withstands over 200°C. Low‑grade and regular silicone may still release toxins when heated. Always check for food‑grade certifications. Choose liquid silicone for tableware and molds to protect your family’s food safety.