Rail transport company Union Pacific (NYSE: UNP) has announced that it has begun testing an experimental technology that can reduce the amount of pollution from a train’s diesel engine through a special chemical process.

We have and will continue to work hard to build the most environmentally friendly locomotive fleet in North America and we are committed to protecting our environment by reducing emissions, said Bob Grimaila, Union Pacific's vice president-environment and safety.

The oxidation catalyst works similar to catalytic converters that are attached to today's automobiles. The special catalytic material chemically reduces the amount of unburned hydrocarbons, carbon monoxide and particulate matter generated by the diesel engine.

Initial testing showed that diesel electric locomotives using ultra-low sulfur diesel (ULSD) fuel with the experimental unit installed reduced particulate emissions by approximately 50 percent, unburned hydrocarbons by 38 percent and carbon monoxide by 82 percent.

Testing will continue in Los Angeles on trains equipped with various sensors and global positioning transmitters, allowing engineers and staff to monitor functioning in real time, the firm said.

The current plans call for one year of testing. No plans for commercialization have been announced.

Shares of Union Pacific were down $1.19 to $94.24 in afternoon trading on the New York Stock Exchange.