c o l u m n

Andrew Ryder • Editor
On Emissions

Burden Must Be Shared

Cleaning diesels must be more than the engine makers’ responsibility.

New engines delivered to California-based truckers now come with a bright yellow warning label attached to them.
     Required under California’s Proposition 65, the warning states plainly that diesel exhaust can cause cancer.
     The label in itself doesn’t make it illegal to use a diesel engine. It simply states a fact.
     Or does it?
     Environmental groups lobbied hard for a ban on diesels in California, claiming that the exhaust was deadly. Yet most researchers and scientists will tell you that we still know precious little about what parts of the exhaust are dangerous and how much of it you can inhale for it to be harmful.
     So little, in fact, that California’s own Air Resources Board could not bring itself to declare diesel exhaust as a whole as a toxic substance.
     Instead, CARB isolated particulates in the exhaust as the culprit. Particulates, it argued, are the most likely part of diesel fumes that cause cancer.
     So while we still have no hard evidence that sharing the air with a diesel-powered truck is deadly, at least we know where we stand: If we can control the particulates, we get to keep our diesels.
     Industry groups have made strong arguments that a lot of the work has already been done. Under federal rules, particulate emissions from new diesels are a fraction of what they were 10 years ago.
     But as the recent Environmental Protection Agency suit against Mack Trucks has shown, keeping particulate limits low in the lab is one thing, but keeping them low after the truck leaves the factory is an entirely different matter.
     We’re used to thinking that the onus to clean up diesels falls squarely on the shoulders of the engine manufacturers. After all, they wield the most influence on the engine’s combustion process and its byproducts.
     But CARB’s decision on diesel exhaust and EPA’s suit have changed things.
     If trucking wants to keep using one of the most efficient energy sources ever discovered by mankind, the responsibility to clean it up must be shared by the following players:
     • Engine makers, who must continue to refine the combustion process to reduce particulate emissions. And they must cooperate with CARB and other regulatory agencies in research on particulates so we can understand exactly what parts of particulates are harmful and how they can be eliminated.
     • Truck manufacturers, who must work closely with engine makers to engineer practical exhaust systems and after-treatment devices that can help lower particulate emissions.
     • Fuel refiners, who must commit to producing cleaner fuel. Right now, California has cleaner fuel than any other state in the nation. Yet its diesel is still not as clean as fuel sold in Western Europe and other parts of the world. Removing sulfur and changing cetane and aromatic levels in diesel can have a huge impact on diesel exhaust.
     • Fuel marketers, who must commit to selling cleaner diesel. Oil companies cannot commit to the huge capital costs involved in modifying refineries to produce cleaner diesel unless they are guaranteed a market for it. They did it in California because the state required it of them. They may do it on a national scale without government intervention if marketers agree to sell it and promote it.
     • You, the truck user, who must take the high road and commit to burning the cleaner diesel when it becomes widely available. Meanwhile, you must commit to keeping engines properly tuned and fuel systems adequately cleaned. Aside from the obvious social benefits, it’ll help you avoid fines. Nine states (New Jersey, California, Connecticut, Arizona, Colorado, Nevada, Ohio, Utah and Washington) are conducting roadside smoke testing and more states will soon join them.
     Although we have been given a reprieve, diesel is still under the microscope.
     And engine makers alone won’t bail you out this time.