Caulks, Sealants & Adhesives

Types of Caulk

The toxicity of caulks and sealants varies depending on the type of product. Knowing these types can help you choose safer products. The words “caulk” and “sealant” are sometimes used interchangeably, as both do similar things, but some manufacturers reserve “sealant” for high-performance products.

• Synthetic rubber caulks contain high levels of VOCs.
• Butyl rubber caulks contain high levels of VOCs, and often contain other chemicals that can lead to serious respiratory problems, including asthma.
• Polyurethane caulks can contain carcinogenic ingredients.
• Silicone caulks may contain harmful fungicides, depending on their formulation.

Keep in mind that safer varieties of caulks and adhesives may not be available at your neighborhood hardware store, even though they have a wide selection of products. Stores that specialize in low-VOC home products or online retailers may provide better options.

Ingredients to Avoid

Each of the following solvents commonly found in caulks, sealants and adhesives are respiratory irritants, but some present additional health hazards.

• Mineral spirits and petroleum distillates can be carcinogenic and harm the nervous system.
• Ethylene glycol is potentially harmful to the kidneys, the liver and the nervous system.
• Methyl ethyl ketone, or MEK, can harm the nervous system.
• Toluene can cause reproductive harm.
• Xylene can harm the nervous system.
• Acetone at high doses may cause nausea, headaches or lightheadedness.

When choosing products, also avoid:

• Caulks and sealants containing dibutyl phthalate and butyl benzyl phthalate. Phthalates are endocrine-disrupting chemicals that can cause reproductive problems.
• Wood or flooring adhesives with phenol- or urea-formaldehyde resins that can emit significant amounts of formaldehyde, a carcinogen.
• Adhesives containing BPA, a potent endocrine disruptor.