Page 509-LEED Reference Guide 2009-SCAQMD 1168 [2005]-Table 1 shows the VOC limits for:
PVC Welding - 510 g/l
Plastic Cement Welding - 250 g/l
Most common brands/manufacturers like Oatey, Ipex, Weld-on are labeling their product name as 'PVC Plastic Pipe Cement' and product use as "solvent cement for PVC Plastic Pipe". Their product VOC is less/equal 510 g/l.
For example - http://www.weldon.com/pdf/weldon/sds/W-O795LoVoc_10-13.pdf
From the Table 1 above, shouldn't the VOC limit for these products be 250 g/l?
Jon Clifford
LEED-AP BD+CGREENSQUARE
LEEDuser Expert
323 thumbs up
January 20, 2015 - 7:13 pm
Welding solvents for ABS, CPVC, and PVC plastics are allowed higher VOC content than the 250g/L limit stipulated for cements used to weld other types of plastic. Read the definition in SCAQMD-1168:
PLASTIC CEMENT WELDING is the use of adhesives made of resins and solvents which are used to dissolve the surfaces of plastic, except ABS, CPVC, and PVC plastic, to form a bond between mating surfaces.
Lilian Seow
PrincipalLSDesignworks @ Vancouver, BC Canada
12 thumbs up
January 21, 2015 - 10:37 am
Thanks Jon. The confusion here is that the contractors are categorizing their 'plastic cement welding' products as plastic cement welding that has a higher voc limit.
And also somewhere in SCAQMD clause says something about using the lowest VOC limit if the product falls under two categories? If this so, then many such products are non-complaint!
Jon Clifford
LEED-AP BD+CGREENSQUARE
LEEDuser Expert
323 thumbs up
January 21, 2015 - 7:40 am
The data sheet that you posted classifies the product as a “Solvent Cement for PVC Plastic Pipe.” Since the cement is intended for PVC, the manufacturer has correctly classified it as a “PVC Welding” product with a 510g/L VOC limit.
A similar product that is not intended for ABS, CPVC, or PVC would meet the definition of a “Plastic Cement Welding” product with a 250g/L VOC limit.
ABS, CPVC, & PVC are all types of plastics typically joined by “Solvent Welding.” SCAQMD assigns a different VOC limit to the cements & solvents used to weld each of these 3 types. The “Plastic Cement Welding” category is a fourth category for cements & solvents used to weld OTHER types of plastic.
Lilian Seow
PrincipalLSDesignworks @ Vancouver, BC Canada
12 thumbs up
January 21, 2015 - 10:38 am
Thanks Jon.
I umderstand there are different categories for different products. For this very same reason, im puzzled as to why manufactured would use the lower VOC when the product is 'cement welding'.
Isnt Plastic Welding for plastic weld rod which is heated to join sheet vinyl?
And strangely but I may have missed it, that there is no definition for this Plastic Welding in SCAQMD doc and website.
Jon Clifford
LEED-AP BD+CGREENSQUARE
LEEDuser Expert
323 thumbs up
January 21, 2015 - 7:14 pm
LS — I see why you are confused. Some flooring systems use a thermoplastic “welding rod” that is inserted into seams and heated to bond adjacent sheets. This is not the type of “welding” that SCAQMD is referring to in its PVC, CPVC, ABS, & Plastic “Welding” categories.
The SCAQMD categories refer to solvents & cements like those used to join plastic piping and conduit. See the following SCAQMD-1168 definition:
SOLVENT WELDING is the softening of the surfaces of two substrates by wetting them with solvents and/or adhesives, and joining them together through a chemical and/or physical reaction(s) to form a fused union.
Also look at the “Plastic Cement Welding” definition posted above.