Wet Strength Resins

Analytical testing dots

Laboratory Analysis of Paper Product Compounds (Wet Strength Component Testing)

Wet Strength ResinWet Strength resins are added to many paper products to prevent them from disintegrating readily in water. Products they may be used in include paper towels, weather resistant packaging, milk cartons, frozen food packages and vegetable boxes.

One common wet strength resin is epichlorohydrin. One of the chemicals used in the production of epichlorohydrin is 1,3-dichloro-2-propanol (1,3-DCP). Both 1,3-DCP and 3-chloro-1,2 propanediol (3-MCPD) are degradation products of epichlorohydrin. The European Union has established two guidelines with respect to allowable levels of these compounds. The FDA has set a maximum level of these compounds that will be allowed in foods and food paperboard packaging and in 2010, both 1,3-DCP and 3-MCPD were added to California’s Proposition 65 list. Proposition 65 requires anyone offering a product for sale or use in California containing substances listed in the proposition to provide a warning label to the public stating the product contains a substance known by the state to cause cancer, but only if that substance poses a 1 in a 100,000 or greater cancer risk.

ALS Environmental has developed a method to analyzes for these compounds in paper products produced in mills where epichlorohydrin wet strength resin is used. The sample is initially extracted in laboratory-grade pure water to separate the analytes of interest. The aqueous extract is passed through a solid phase extraction (SPE) column and the compounds are subsequently eluted from the column with solvent. The solvent is further concentrated and then derivatized with heptafluorobutyrylimidazole. A portion of the derivitized extract is injected into a Gas Chromatograph (GC), separated on a capillary column, and the derivatized target compounds are measured by an Electron Capture Detector (ECD).

Analytical testing dots

Learn more about Cardboard Testing...