Silicone caulk is beloved as a sealant for its durability, flexibility, and natural resistance to high temperatures and extreme weather conditions. Its heat resistance makes it ideal for many high-temperature uses, from gaskets and vents to automotive repairs.

However, like all materials, silicone will eventually burn if exposed to high enough temperatures for a long time. Anyone using this kind of sealant should know what happens if it burns, even if it’s unlikely to happen.

Is Silicone Sealant Flammable?

Generally, this kind of sealant is not flammable under normal circumstances. These consumer products are heat resistant, making them popular for kitchens and home use. Most silicone caulks are rated to withstand temperatures as high as 650 degrees Fahrenheit. Some compounds are rated for even higher temperatures.

Silicone caulks mixed with compounds containing different methyl groups could be more flammable than others. That’s why it’s important to understand the contents of the caulk you use. Food-grade versions like the Food Grade 100% RTV Silicone Sealant are popular for areas like kitchens. This is due to its safety with food products and high heat resistance.

Like any compound, silicone can burn if exposed to high enough temperatures. Though these temperatures don’t occur in most regular uses, some silicone products in kitchens and restaurants could reach those temperatures. However, these compounds will not catch fire, instead becoming brittle or causing the seal to deform.

The Byproducts of Burning Silicone Sealant

While most uses for silicone sealants will never reach the burning point, knowing what happens when it does burn is still helpful. This kind of caulk is chemically neutral, meaning it does not release volatile organic compounds (VOCs) when it burns.

Burning silicone sealants in fresh air situations typically leads to the creation of silica, which is sand or glass. This will not produce any harmful toxic gases. These sealants also produce carbon oxides when burned, which are transparent gases and are not harmful to humans when inhaled.

If gassing occurs when a silicone rubber product is exposed to extreme temperatures, it should not significantly affect indoor air quality. This sealant off-gassing does not produce gases that will be toxic when inhaled. Typically, any dangers will be associated with the area around the silicone compounds, not the sealant itself.

Safest Types of Silicone Sealant

Still concerned about the potential for silicone sealant to burn under high temperatures? There are many options to protect your work when caulk reaches high temperatures. Silicone is a stable, durable choice for kitchens and restaurants, with food-grade versions receiving FDA approval for food safety within the kitchen. Food-grade silicone polymer is popular in cooking utensils, with its flexibility and heat resistance making it an excellent choice for high-temperature situations.

For other heating situations like furnaces and gaskets, many sealants are tailor-made for specific high-temperature uses. Xtreme Gasket 100% RTV Silicone Sealant is often used in automotive repair for high-temperature areas of vehicles like gearboxes, engines, and exhaust manifolds, among others.

Silicone's heat-resistant and durable nature makes it a common choice for automotive repairs. If you want to fix a furnace, Hi-Temp Red & Blue 100% RTV Silicone Sealant is also a practical option for homeowners looking to repair their furnace or HVAC system. High-temperature silicone caulk is safe for exposure to temperatures up to 650 degrees Fahrenheit for multiple hours.

How Silicone Stacks Up to Other Compounds

This kind of sealant is a popular choice for many sealing jobs in the home, but how does it stack up to other options? Compared to plastics, it has plenty of advantages as a sealant. Unlike many plastics, it will not produce toxic gases at high temperatures and is more heat-resistant and durable than plastic. It is also generally more resistant to extreme temperatures than plastic compounds, allowing it to last longer as a material in areas like kitchens and restaurants.

Silicone compounds often find use in construction purposes, where solid wood has long been one of the most popular materials. While wood filler is generally more popular for smaller purposes like filling nail holes, silicone creates long-lasting and durable bonds. Silicone is a popular choice for doors and windows due to its flexibility when cured, allowing it to bend and move.

While silicone rubber comes from the same organic group as rubber, there are plenty of differences between the two. Rubber generally features much more tensile strength, meaning that even though silicone is known for its elasticity, rubber will still generally be more flexible. However, silica-based products typically have higher resistance to outdoor weather conditions, making them a go-to for deck and patio repairs.

While you can use silicone and drywall spackles for similar purposes, each has its advantages. Spackle is better suited for filling holes in walls and chips in wood due to its stiffness and ability to be sanded. Silicone caulk, on the other hand, is the preferred choice for filling gaps and cracks in walls, like those around wooden trim or gaps in windows and doors.

Choosing the Right Adhesive with Silicone Depot

If you’re looking for a trusted silicone sealants and accessories supplier, Silicone Depot has a range of sealants for any purpose. Silicone is renowned for its thermal stability and weather resistance. Sealants like the Pro Grade RTV Silicone Sealant can be an effective material for various jobs.

Many sealants, like our Kitchen and Bath Mildew-Resistant sealant, are excellent choices for sealing up those moisture-heavy areas of the home without worrying about mold or mildew. Check out our expansive selection of caulks and sealants to learn more!