CIPP Industry Defends Styrene Use

Fed Dept. Seeks To Label Styrene As ‘Reasonably Anticipated Carcinogen’
By Jeff Griffin, Senior Editor | May 2011, Vol. 66 No. 5
Styrene. Image: Bill Abbott.

Styrene is naturally occurring in the environment, dissipates quickly in the atmosphere and is highly biodegradable in the presence of water. In fact, styrene can be found in common foods such as strawberries and cinnamon. One reason that styrene may be such a target is its pungent odor (if it smells bad, it must be bad), and its low detection level. Most people can smell styrene in the air at the low concentration of less than one part per million.

It is estimated that about 10 percent of the styrene used in North America is for manufacturing composites, which includes cured-in-place-pipe (CIPP). The other 90 percent is used in the manufacturing of many other products such as polystyrene plastic (Styrofoam) and thermoplastics.

Styrene is a principal ingredient of the thermoset resins used in cured-in-place-pipe which is composed of a composite material. Without styrene, this type of cost-effective sewer rehabilitation would not be possible, leaving CIPP contractors, and ultimately sewer system operators, looking for other CIPP resins to use for pipeline rehabilitation. Although styrene substitutes exist, none can match styrene in performance, cost and availability of supply.

CIPP consumes about 5 percent of the styrene used for composite manufacturing, or about 0.5 percent of the total styrene used in North America. Although CIPP consumes millions of pounds of styrene per year, it is a relatively small consumer compared to the entire styrene industry. This means that if all styrene consumers begin searching for styrene substitutes, the CIPP industry may have difficulty finding a reliable supply because larger consumers would have priority purchasing power. (This brief summary of styrene’s uses is based on information provided by NASSCO.)

WSSC and CIPP

Andrew Fitzsimons, project manager for the Washington Suburban Sanitary Commission (WSSC), offers this comment about styrene and cured-in-place-pipe (CIPP) rehabilitation.

“CIPP lining provides system owners with a valuable, low-cost alternative to traditional open-cut construction. Listing styrene as a ‘reasonably anticipated carcinogen’ will likely result in a drastic increase in the cost of CIPP rehabilitation. As CIPP costs approach that of open-cut, system owners like WSSC will increasingly choose open-cut pipe over CIPP. Losing this lower-cost alternative will increase the capital costs associated with failing pipeline infrastructure replacement, particularly those mandated by EPA consent decrees. These costs will be passed on to the rate payers.”