Dow Corning Cookie Policy

We use cookies to enhance your experience with Dow Corning. Learn how cookies are used on this website and view our privacy statement.

By continuing to browse this site, you agree and consent for cookies to be used.

Silicones from Dow Corning
Log In | Profile/Preferences | Customer Support | Contact Us      Global (English). Change
Products             Technical Library             Premier Services             About Dow Corning             Careers
Discovery Center Home
Silicone Showcase
Safety & Sustainability
Proven Innovation
Chemistry Corner
Physical & Chemical Properties
Tailoring Properties & Performance
Organically Modified Silicones
Cure Systems
How Silicones Work
Silicone Manufacturing
Fascinating Silicone™ Chemistry Corner – Environmental Degradation

How polydimethylsiloxane degrades in the environment

When polydimethylsiloxane (PDMS) polymers contact clay minerals in the soil, their siloxane backbone depolymerizes into lower-molecular-weight materials – primarily Me2Si(OH)2. Depending on soil type, this dimethylsilanediol will undergo further degradation:

  • Either in the soil via biodegradation
  • Or through evaporation into the atmosphere, where it will degrade oxidatively via reaction with hydroxyl radicals

Whether degradation occurs in the soil or in the air, the result is the same. The PDMS polymer breaks down into naturally occurring materials:
  • Silicates that exist naturally in the soil
  • Amorphous silica
  • Carbon dioxide
  • Water vapor

How PDMS enters the environment

PDMS fluids – Low-molecular-weight PDMS polymers are primarily used in personal and household care products, like shampoos, conditioners, and detergent antifoams. These products are rinsed away after use and end up in municipal wastewater treatment plants. High-molecular-weight PDMS fluids used as process aids, or surface treatments in industrial applications also end up in wastewater treatment facilities.

High-molecular-weight PDMS molecules are virtually insoluble in water. This, combined with their tendency to bind with organic material, effectively removes them from the wastewater and onto the sludge during wastewater treatment. This sludge is either used as a soil conditioner or it is incinerated. Either way, the PDMS will break down into the same naturally occurring materials: silicates, amorphous silica, carbon dioxide, and water vapor.

Solid silicones – Solid silicones such as PDMS-based rubbers or sealants may be used in the home (as bathtub caulk or baby bottle nipples) or in industrial applications, such as textile coatings, electronics protection materials, moldmaking rubber, or rubber gaskets. They enter the environment as a component of domestic or industrial waste, where they will be either landfilled or incinerated. Many silicone rubber elastomers can be reclaimed and recycled into new materials. This not only keeps them out of the landfill, but extends their useful lives.

Learn how different types of silicones work.

 Did you know ... studies have shown that the application of sludge containing PDMS to the soil does not appear to affect crop growth or soil organisms.

Expand your understanding

Learn more about:
Silicones and their Impact on the Environment (PDF Size 56KB)
An Overview of PDMS in the Environment (PDF Size 35KB)
An Overview of VMS Fluids in the Environment (PDF Size 79KB)
Polydimethylsiloxanes Do Not Bioaccumulate (PDF Size 34KB)
Fate and Effects of Polydimethylsiloxane in Marine Environments - Article reprint from the Marine Pollution Bulletin (PDF Size 4.2MB)

Explore your material options

Get answers

Have a question about how silicones degrade in the environment?

Ask an Expert

Silicone environmental expert

Stay informed
Sign up for free e-mail updates about silicone materials and technologies from Dow Corning.

Media Center    |    REACH    |    Site Map    |    Other Dow Corning Websites         
Using this website means you understand our Privacy Statement and agree to our Terms & Conditions.
©2000 - 2018 Dow Corning Corporation. All rights reserved. Dow Corning is a registered trademark of Dow Corning Corporation, a wholly owned subsidiary of The Dow Chemical Company.
The Corning portion of the Dow Corning trademark is a trademark of Corning Incorporated, used under license. XIAMETER is a registered trademark of Dow Corning Corporation. We help you invent the future is a trademark of Dow Corning Corporation.®™Trademark of The Dow Chemical Company ("Dow") or an affiliated company of Dow.
Dow Corning complies with the California Transparency in Supply Chains Act.