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Is Water Based Aerosol Paint Safe to Use?
- Lead free?
- CFC free?
- Halogenated solvent free?
- Safe for the Ozone layer?
'Safe to use' / Lead Free / CFC free
'Safe to use'/ 'Lead free' and 'CFC free' declarations
are commonly used on aerosol cans sold in Australia.
CFC'S (Chlorofluorocarbons)
CFC'S have been universally phased out since their effect
on the ozone layer has been confirmed over the last 30-40
years.
The term 'halogenated' refers to chemicals termed halogens
such as Fluorine, Chlorine, Bromine and Iodine as found on
the periodic table.
In coatings we normally refer to 'haloalkane' solvents and
propellants that consist of chlorine and/or fluorine groups
locked onto a small organic compound called an 'alkane'.
Halogenated solvents include methylene chloride and
trichloroethylene are still used for some paints, in dry
cleaning and in paint strippers due to their excellent
solubility.
One peculiar reason for using halogenated solvents and
propellants in aerosols is their weight.
Aerosol paint cans are commonly sold by weight and, as CFC
propellants and solvents are heavier than paint, less paint
can be used in the can while still giving the same total
weight.
LEAD FREE
It is illegal for any Paint company in Australia, to
manufacture any paints containing lead and/or chrome based
pigments.
Some examples of outlawed 'heavy metal' pigments include
white lead, molybdate orange, lead chromate, lead silicate,
lead cyanamide, and lead chrome.
These mainly cover the color ranges from white, yellow, red
and orange and may also be used for anticorrosive and flame
retardant properties.
Some of these pigments were used by Chinese manufacturers in
the Mattel Toy scandal of 2008. Unfortunately it has been
confirmed heavy metal pigments are extremely hazardous,
particularly with regards to young children as they affect
the development of brain cells and nervous systems when
growing.
Unlike a lot of other toxins, 'heavy metals' such as lead
compounds and mercury for example are not excreted by the
body but are cumulative.
PROPELLANTS
A range of non flammable aerosol propellants called
FreonTM were developed by Dupont in the 1930's.
FreonTM represents several different chlorofluorocarbons (CFC's)
and contains the elements carbon, fluorine, chlorine and
hydrogen. The FreonTM range are colorless, odorless, non
flammable, and non corrosive. They were successfully used as
propellants until the 1970's until their depletion of the
ozone layer became widely known.
A blanket ban was put on all volatile halogenated solvents,
of which FreonTM is a member, when they were identified as
severely damaging the ozone layer.
The extremely damaging CFC's have been replaced by aliphatic
propellants such as butane and propane however a safer
option for the environment is the dimethyl ether propellant
used in water based aerosol paints.
Dimethyl Ether Propellant
- No Ozone depletion potential (ODP)
- Very low green house warming potential (GWP)
- Photochemical ozone creation potential (POCP) half
of hydrocarbons
- Lifetime in the atmosphere is half of hydrocarbons
before decomposing to carbon dioxide
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