Costa Rica has joined many other countries in limiting the amount of sulfur in diesel fuel to 50 parts per million.
President Laura Chinchilla Miranda signed a decree to that effect Wednesday. Such a limit has been the standard in the European Union since 2005. This is the standard in some South American countries, too, but Casa Presidencial said that other Central American nations permit sulfur as high as 500 parts per million.
When it is expelled as exhaust, sulfur can cause acid rain and affect human health.
Sulfur is naturally occurring in petroleum, and the refining process can remove or limit the amount. Petroleum from different oil fields have different percentages of sulfur.
Costa Rica has a contract with British Petroleum, and the first boatload of 6.7 million barrels arrived in November, said Casa Presidencial.
Petroleum is a state monopoly through the Refinadora Costarricense de Petróleo, S.A. The country imports all of its petroleum.
By reducing the amount of allowable sulfur, the administration expects to reduce the sulfur emissions by 90 percent. From January to September, officials estimate, some 658 tons of sulfur went into the nation’s air under the 500-parts-per-million standard. They expect to cut the emissions to 66 tons for an equivalent period. The new product is called Diesel 50.
Some countries have a standard of ultra low sulfur diesel where only 15 parts per million is permitted.