Combined effects of termiticides and mechanical stress on chlorinated polyvinyl chloride (CPVC) pipe.
BACKGROUND
CPVC pipe failures have recently been reported beneath structures as a result of termiticide soil treatments. To determine whether these CPVC failures were actually caused by termiticides, CPVC tubes were filled with 50 mL of either termiticide concentrate, dilutions or treated builder's sand and sealed. Mechanical stress was added to these sealed tubes by hanging bricks from their ends.


RESULTS
As concentrates, eight of nine emulsifiable concentrates tested caused failure within 8 weeks. None of the three suspensible concentrates tested caused failure over this period. Dilution of emulsifiable concentrates caused progressively fewer CPVC tube failures. No treated soils caused tube failures. Excessive CPVC glue applications in combination with chlorpyrifos 440 g kg(-1) EC (Dursban(trade mark) TC) degraded the CPVC. All volatile organic compounds (VOCs) found in the termiticide formulations caused CPVC tube failure within 1 week as pure chemicals. The VOC 1,3,5-trimethylbenzene caused CPVC tube failure within minutes of exposure. This VOC was found in all termiticides that caused failures as concentrates.


CONCLUSIONS
It is highly improbable that a properly conducted preconstruction soil treatment, where termiticide is completely adsorbed to the soil, would be solely responsible for CPVC pipe failure. Manufacturers should consider removing 1,3,5-trimethylbenzene from termiticide formulations to minimize the risk of CPVC pipe failure.
Smith
Joseph A
JA
Department of Entomology and Nematology, University of Florida, Gainesville, FL 32611, USA.
Saunders
Justin
J
Koehler
Philip G
PG
D000269:Adhesives / Q000737:chemistry; D000818:Animals; D006843:Hydrocarbons, Chlorinated / Q000737:chemistry*; D007306:Insecticides / Q000737:chemistry*; D010573:Pesticide Residues / Q000737:chemistry*; D011143:Polyvinyl Chloride / Q000737:chemistry*; D012822:Silicon Dioxide; D012987:Soil / Q000032:analysis; D013314:Stress, Mechanical; D013997:Time Factors; D014835:Volatilization; D014867:Water
D000269:Adhesives; D006843:Hydrocarbons, Chlorinated; D007306:Insecticides; D010573:Pesticide Residues; D012987:Soil; D014867:Water; D012822:Silicon Dioxide; D011143:Polyvinyl Chloride