[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

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.

John Salmen



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.


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)). 


-    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 
     indoor spraying. 

-    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 
        site, and  
     -  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 
        protective equipment.

-    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 
        be non-sparking. 
     -  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 
        involving isocyanates. 
     -  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. 
G40michael@aol.com wrote:
> I am currently building a home in mid-Michigan.  One of the local
> insulating
> contractors offers spray ureathane foam.  This product is ported to be
> non-
> 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
> foam
> 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
> ______________________________________________________________________
> This greenbuilding dialogue is sponsored by CREST <www.crest.org>
> Environmental Building News <www.ebuild.com> and Oikos <www.oikos.com>
> For  instructions send  e-mail to  greenbuilding-request@crest.org.
> ______________________________________________________________________
This greenbuilding dialogue is sponsored by CREST <www.crest.org>
Environmental Building News <www.ebuild.com> and Oikos <www.oikos.com>
For  instructions send  e-mail to  greenbuilding-request@crest.org.

Follow-Ups: References: