Where did you get that Rob?

I don't know anything specific about epoxy components, but I don't know why that would be necessarily true.

Well perhaps I'm wrong, but I remember this discussion a number of times and statements saying West's more concentrated hardeners were more sensitizing. The source is lost somewhere in my gray cells.

Hazards
The primary hazard associated with epoxy involves skin contact. WEST SYSTEM Resins may cause moderate skin irritation. WEST SYSTEM Hardeners are corrosive and may cause severe skin irritation. Resins and hardeners are also sensitizers and may cause an allergic reaction similar to poison ivy. Susceptibility and the severity of a reaction varies with the individual. Although most people are not sensitive to WEST SYSTEM Resins and Hardeners, the risk of becoming sensitized increases with repeated contact. For those who become sensitized, the severity of the reaction may increase with each contact. These hazards also apply to the sanding dust from epoxy that has not fully cured. These hazards decrease as resin/hardener mixtures reach full cure. Refer to product labels or Material Safety Data Sheets for specific product warnings and safety information.

But here is West's info - http://www.westsystem.com/ss/health-effects-from-overexposure-to-epoxy/

And - http://www.fram.nl/workshop/controlled_vacuum_infusion/allergy.htm

Whatever you use take precautions.

Rob