Tier 4 Regulations

The original goal: Emissions reduction
Since the introduction of Tier 1 emissions standards in 1996, nitrogen oxide (NOx) and particulate matter (PM) have been reduced by 60 percent.

NOx: Nitrogen oxide and nitrogen monoxide are produced during combustion when the engine is at its hottest.

PM: Particulate matter – tiny carbon particles and other harmful material – is created when not all fuel is burned during combustion, usually when the engine is cooler.

The Tier 4 goal: Near-zero levels of PM and NOx emissions
The Tier 4 final emissions regulations call for a 90-percent reduction in PM and NOx – the most significant reduction in heavy equipment emissions to date.

Timing
Tier 4 regulations will be introduced in two phases:

• Phase 1 – Tier 4 interim standards
  Beginning in 2011, Tier 4 interim standards will require a significant reduction of PM and NOX. Exhaust emission levels of hydrocarbons (HC) and carbon monoxide (CO) will also be regulated.
  
• Phase 2 – Tier 4 final standards
  Tier 4 final standards begin in 2014 and will require an even more substantial reduction in PM and NOx.