Crown boiler training

Spent a nice day yesterday with Walt Tittermary at a hydronics training session sponsored by our local Johnstone supply. Walt brought up one really thought provoking/scary topic which is that Charlotte Pipe the largest PVC supplier is reminding us all that the product has NO astm reference to combustion gas venting only liquids, like sewer pipe. Since there's a 140 degree max temp mentioned for the pipe all of us think it must be OK for venting combustion gas and some liquid condensate. Maybe, but it hasn't been tested as to an astm spec. Just think millions of 90 plus furnaces where the manufacturer references an astm standard for venting that may not apply.