Arguing the law entitles them to clean hopper cars, shippers have asked the Interstate Commerce Commission to suspend a revised tariff filed by Illinois Central Railroad holding them liable for damages when freight is contaminated by dirty railcars.

"The tariff matter seeks to insulate the carrier from its own negligence in furnishing a contaminated car," said the joint protest, filed by the Chicago Board of Trade and IMC Fertilizer Group Inc. of Mundelein, Ill.IMC and the Chicago Board of Trade, along with five other grain shippers, attacked an earlier Illinois Central tariff that held shippers responsible for inspecting covered hopper cars when received.

Under that tariff, if the railcars were found to be contaminated, shippers were required to either reject them or clean them at their own expense. Following a storm of shipper criticism, Illinois Central withdrew the earlier tariff and substituted a revised one, set to take effect Tuesday.

Under the revised tariff, shippers are not directed to clean dirty cars, but remain responsible for making a reasonable inspection. This means they remain liable for damages arising from contamination, said Thomas F. McFarland Jr., an attorney with the Chicago law firm of Belnap, Spencer, McFarland & Herman, which represents the two shippers.

The revised tariff still violates the Carmack Amendment to the Interstate Commerce Act, which holds carriers responsible for full liability if goods hauled by them are damaged in transit, except in certain circumstances, said the National Industrial Transportation League, which also has protested to the ICC. It also violates the Sanitary Food Transportation Act of 1990, the NITL said.

While the language in the current tariff was chosen more carefully than that in the earlier version, it is still clear that the aim of the current tariff would be to require shippers to bear the expense of cleaning covered hopper cars that should be cleaned by Illinois Central, Mr. McFarland said.