An Overview of Polydimethylsiloxane (PDMS) Fluids in the Environment0 pages

An Overview of
Polydimethylsiloxane
(PDMS) Fluids in the
Environment
Environmental Information - Update

Health Environment & Regulatory Affairs (HERA)

Summary of Use:

Environmental Entry:

Most polydimethylsiloxane fluids are non-volatile
polymeric organosilicon materials consisting of
-(CH3)2SiO- structural units.

Due to the wide range of applications for PDMS
fluids, they can enter the environment in a variety of
ways. Since they are non-volatile, they do not
evaporate into the atmosphere. In household products,
very small amounts of PDMS fluids may be washed
from the surfaces to which they’ve been applied and
eventually into the soil or a wastewater treatment plant
(WWTP).

CH3

CH3

Si O

Si O

Si

CH3

CH3

CH3

CH3

n

CH3

CH3

typically, n > 4*
Various PDMS fluids ranging from low to high
viscosity are used in a wide range of industrial
applications, such as manufacturing textiles, paper,
and leather goods1. In these industries, PDMS fluids
are highly-efficient process aids, able to provide
desirable properties at very low concentrations. They
often serve as antifoams, softeners, or water
repellents.
In consumer applications, PDMS fluids can be found
in personal-, household- and automotive care
products.1 They are used as softeners in skin care
products, conditioners in hair care, additives in polish
formulations, waterproofers and as a component of
other surface treatments. Some PDMS materials are
also sold as end products (usually in the industrial
market), such as transformer dielectric fluids and heat
transfer liquids.

For example, personal care products such as
shampoos and conditioners are rinsed away after use,
and the PDMS they contain is carried with wastewater
to the treatment site. This could be a private septic
system or municipal plant. When PDMS fluids are
used in industrial applications such as process aids
or surface treatments, small quantities can also be
found in process wastewater that is carried to the
treatment plant. Of the total PDMS production volume
worldwide, about 17% is used in “down-the-drain”
applications. End-use industrial products such as
transformer fluids are used in contained applications.
These are suitable for recycling and are therefore
unlikely to enter the environment except in cases of
accidental release.

* Materials with n=4 or less are referred to as VMS
(volatile methylsiloxane)
Ref. n° 01-1034A-01

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© Copyright Dow Corning Corp., 1997. All rights reserved.

Last Revision 04/98