Water-based
vs. Solvent-based
 Generally, consumers can choose between two types of paints:
• Water-based paints
•
Solvent-based paints
As their name indicates, solvent-based paints, sometimes
referred to as "oil-based" or "alkyd" paints,
contain a significantly higher level of organic solvents
than water-based paints. These solvents are responsible for
the strong odour noticeable in buildings that have been freshly
painted. They are also potentially hazardous for both human
health and for the environment which is why concerted efforts
are being made to reduce or remove their presence in paints
without negatively impacting on paint performance.
Today, water-based paints dominate and account for roughly
80% of paints sold in the residential market.
The function of organic solvents in a paint relates to certain
properties it brings – it facilitates the paint’s
application, it’s drying, and the formation of a regular
paint film. During application and drying, the solvent evaporates.
Ideally a dry paint film no longer contains solvent. However
when they evaporate, these solvents release Volatile Organic
Compounds (VOCs) into the atmosphere, with a negative, toxic
impact on the environment.
| PQI
Tip: A simple way of finding out if a paint
is water-based or solvent-based is to check on the
label about how to clean brushes. Solvent-based paints
need to be cleaned with white spirit or turpentine,
water-based paints can be cleaned with warm, soapy
water. |
Fifty years ago, virtually all paint was solvent-based.
Today, advances in paint technology mean that modern, water-based
paints, often referred to as acrylic emulsions, are increasingly
replacing organic solvents across a broad range of paint
applications and surface areas (and account for 80% of architectural
paints). Legislation is in place to support this trend.
Spear headed by (but not limited to) to regulatory developments
in California, we continue to see stricter paint VOC regulations
across the US and Canada. In terms of total VOC’s,
100 g/l paints are very common today. And predictions are
that most manufacturers will have 50 g/l in the near future.
For
an overview of regulations to date see link below:
http://www.paintquality.com/contractor/newsletters/contNL1006.html
From a performance standpoint, advances in paint technology
mean that high quality water-based paints are in many respects
equal to or superior to their solvent-based equivalents.
High quality acrylic emulsions offer excellent durability,
quick drying time, and the emission of less odor.
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