Emerson Process Management ControlWave XFC - Manual (Page 151)

DOW CORNING CORPORATION
Material Safety Data Sheet
Page: 5 of 7
DOW CORNING 200(R) FLUID, 100 CST.
12. ECOLOGICAL INFORMATION
Environmental Fate and Distribution
Air:
This product is a high molecular weight liquid polymer which has a very low vapour
pressure (<1 mm Hg). As a result it is unlikely to become an atmospheric contaminant
unless generated as an aerosol.
Water:
This product has a very low water solubility (< 100 ppb). As it has a specific gravity of < 1,
if discharged to water, it will initially form a surface film. As the product is non volatile and
has a high binding affinity for particulate matter, it will adsorb to particulates and sediment
out.
Soil:
If discharged to surface water, this product will bind to sediment. If discharged in effluent
to a waste water treatment plant, the product is removed from the aqueous phase by
binding to sewage sludge. If the sewage sludge is subsequently spread on soil, the
silicone product is expected to degrade.
Degradation:
This product, polydimethylsiloxane, degrades in soil abiotically to form smaller molecules.
These in turn are either biodegraded in soil or volatilized into the air where they are
broken down in the presence of sunlight. Under appropriate conditions, the ultimate
degradation products are inorganic silica, carbon dioxide and water vapour. Due to the
very low water solubility of this product, standard OECD protocols for ready and inherent
biodegradability are not suitable for measuring the biodegradability of this product. The
product is removed >80% during the sewage treatment process.
Environmental Effects
Toxicity to Water
Organisms:
Based on analogy to similar materials this product is expected to exhibit low toxicity to
aquatic organisms.
Toxicity to Soil Organisms:
Experiments show that when sewage sludge containing polydimethylsiloxane is added to
soil, it has no effect on soil micro-organisms, earthworms or subsequent crops grown in
the soil.
Bioaccumulation:
This product is a liquid and is a high molecular weight polymer. Due to its physical size it
is unable to pass through, or be absorbed by biological membranes. This has been
confirmed by testing or analogy with similar products.
Fate and Effects in Waste Water Treatment Plants
This product or similar products has been shown to be non-toxic to sewage sludge bacteria.
Ecotoxicity Classification Criteria
Hazard Parameters (LC50 or EC50) High Medium Low
Acute Aquatic Toxicity (mg/L) <=1 >1 and <=100 >100
Acute Terrestrial Toxicity <=100 >100 and <= 2000 >2000
This table is adapted from "Environmental Toxicology and Risk Assessment", ASTM STP 1179, p.34, 1993.
This table can be used to classify the ecotoxicity of this product when ecotoxicity data is listed above. Please read the other information presented
in the section concerning the overall ecological safety of this material.
13. DISPOSAL CONSIDERATIONS