ARB RELAXATION OF NO2 LIMIT FOR DIESEL TRAPS DRAWS CONCERNS

Despite the potential for unhealthful levels of nitrogen dioxide (NO2) emissions from advanced particulate matter (PM) trap technology for diesel engines, the air board last week relaxed an NO2 standard to maintain a steady decline in overall PM. While concerned about exposure to sensitive populations, including schoolchildren, of NO2, air officials say relaxing the standard will benefit the population as a whole by maintaining a robust PM emission control device market. The diesel emission control technology rules are considered critical...