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Re: GBlist: ureathane foam
I'm not sure exactly the form of spray foam your are referring to,
traditionally concerns with polyurethane foams have been with expanding
or blowing agents and their contributions to ozone deplition. I think
Icynene (sp.?) is a non cfc or hcfc foam but as far as I know they all
contain isocyanates, among other things, for which their is some info.
Polyurethane foam is being used more and more as an insulation
material in residential construction. Recent experience
indicates that some contractors may not be providing workers who
handle it with adequate respiratory protection or training in
proper work and hygiene practices.
Polyurethane foam is usually prepared on site in a closed system.
The following materials are mixed in a 1:1 ratio:
- base resin, comprising polyols, amines (often tertiary
amines) to act as catalyst and plasticizers; and
- isocyanate (both monomeric and polymeric), usually
methylene bisphenyl isocyanate (MDI).
Normally, two workers are involved in spraying the foam: a
sprayer and a helper who cuts off excess foam and cleans it up.
To clean the spray gun, the workers use an organic solvent such
as glycol ether (ethylene glycol monoethyl ether).
When sprayed, materials that contain isocyanates can cause
primary irritation, sensitization and allergic reactions. The
main organs affected are the respiratory system, the eyes and the
skin. Long-term effects include chronic bronchitis and asthma.
Exposure to the vapour of the tertiary amine, which is normally a
component of the catalyst in producing the foam, may cause eye
irritation. This may result in temporary blurred vision or the
appearance of a blue haze or halo around lights. There is a
safety hazard if a worker's vision is severely affected.
Tertiary amines may also cause allergic asthmatic reactions.
Repeated or prolonged skin contact with the organic solvents used
in cleaning may result in skin irritation or rashes. Glycol
ether may be absorbed in significant amounts through intact skin.
LOCATIONS AND SECTORS
Residential and commercial construction.
The construction sector is exempt from the Isocyanates Regulation
(RRO 842/90), but the requirements of the WHMIS Regulation (RRO
860/90) do not apply to construction. A draft regulation on
isocyanates on construction projects is being developed.
The Occupational Health and Safety Act states:
"An employer shall take every precaution reasonable in the
circumstances for the protection of the worker" (s. 25(2)(h)).
PRECAUTIONARY MEASURES FOR SPRAYING POLYURETHANE FOAM
- Both the sprayer and the helper must use the appropriate
class of air-supplying respirator operated in pressure-
demand or other positive-pressure mode while polyurethane is
being sprayed. If compressed air is used for respirators,
it must meet applicable CSA Standards.
- The Construction Safety Association of Ontario recommends
that a roped-off safety area should be established around
the spraying operation for the protection of other workers.
The boundary should be three metres (10 ft.) from the
operation for outdoor spraying and eight metres (25 ft.) for
- Anyone working within three metres (10 ft.) of the operation
must wear full protective clothing and respiratory
protective equipment (see the ministry's Guide to Isocyanate
Regulation, page 26).
- Ensure that:
- polyurethane components are properly labelled.
- the proper Material Safety Data Sheets are available on
- workers have been trained as required by the WHMIS
- In particular, workers must be trained by a competent person
- the hazards of exposure to isocyanates, organic solvents,
and tertiary amines,
- proper work and hygiene practices, and
- proper use, maintenance and cleaning of respiratory
- Work and hygiene practices should include the following:
- Provide adequate ventilation to the outdoors from the
work area. If mechanical ventilation is used, fans must
- Prohibit any potential source of ignition in the work
- Clean and decontaminate equipment used in handling
isocyanates promptly after using it.
- Prohibit eating, drinking and smoking in the work area.
- Avoid skin contact with isocyanates and organic solvents:
for example, wear polyvinyl alcohol gloves for protection
against isocyanates, or chlorinated polyethylene gloves
for isocyanates and ethers. Chemical resistance may vary
among different products made of the same material, so
the resistance of protective clothing should be evaluated
under conditions of use.
- Wash hands and face before eating, drinking, smoking and
going to the washroom and upon completion of work
- Clean up and dispose of spilled components promptly.
Each mobile spraying unit should carry a spill kit. This
should contain decontaminants for the isocyanate
components (these decontaminants form more stable
compounds that can be disposed of safely) and absorbent
materials for the polyol/amine catalyst mixture.
> I am currently building a home in mid-Michigan. One of the local
> contractors offers spray ureathane foam. This product is ported to be
> toxic and having a R-8.14/in. This seems wonderful, and I am
> considering its
> use. The only drawback I can figur' is that it will be impossible to
> run any
> addition wiring in these wall at a later time. I would be using the
> only on exterior(2x4) walls( Foundation to top plate) Does anybody
> have any
> experience with this product? It seems like a wonderful product.
> G. Michael Molnar
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