[Code of Federal Regulations]
[Title 40, Volume 30]
[Revised as of July 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR1039.240]

[Page 496-497]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 1039_CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD 
COMPRESSION-IGNITION ENGINES--Table of Contents
 
                  Subpart C_Certifying Engine Families
 
Sec. 1039.240  How do I demonstrate that my engine family complies with 
exhaust emission standards?

    (a) For purposes of certification, your engine family is considered 
in compliance with the applicable numerical emission standards in Sec. 
1039.101(a) and (b) or in Sec. 1039.102(a) and (b) if all emission-data 
engines representing that family have test results showing deteriorated 
emission levels at or below these standards. (Note: if you participate 
in the ABT program in subpart H of this part, your FELs are considered 
to be the applicable emission standards with which you must comply.)

[[Page 497]]

    (b) Your engine family is deemed not to comply if any emission-data 
engine representing that family has test results showing a deteriorated 
emission level above an applicable FEL or emission standard from Sec. 
1039.101 for any pollutant.
    (c) To compare emission levels from the emission-data engine with 
the applicable emission standards, apply deterioration factors to the 
measured emission levels for each pollutant. Section 1039.245 specifies 
how to test your engine to develop deterioration factors that represent 
the deterioration expected in emissions over your engines' full useful 
life. Your deterioration factors must take into account any available 
data from in-use testing with similar engines. Small-volume engine 
manufacturers may use assigned deterioration factors that we establish. 
Apply deterioration factors as follows:
    (1) Additive deterioration factor for exhaust emissions. Except as 
specified in paragraph (c)(2) of this section, use an additive 
deterioration factor for exhaust emissions. An additive deterioration 
factor for a pollutant is the difference between exhaust emissions at 
the end of the useful life and exhaust emissions at the low-hour test 
point. In these cases, adjust the official emission results for each 
tested engine at the selected test point by adding the factor to the 
measured emissions. If the factor is less than zero, use zero. Additive 
deterioration factors must be specified to one more decimal place than 
the applicable standard.
    (2) Multiplicative deterioration factor for exhaust emissions. Use a 
multiplicative deterioration factor if good engineering judgment calls 
for the deterioration factor for a pollutant to be the ratio of exhaust 
emissions at the end of the useful life to exhaust emissions at the low-
hour test point. For example, if you use aftertreatment technology that 
controls emissions of a pollutant proportionally to engine-out 
emissions, it is often appropriate to use a multiplicative deterioration 
factor. Adjust the official emission results for each tested engine at 
the selected test point by multiplying the measured emissions by the 
deterioration factor. If the factor is less than one, use one. A 
multiplicative deterioration factor may not be appropriate in cases 
where testing variability is significantly greater than engine-to-engine 
variability. Multiplicative deterioration factors must be specified to 
one more significant figure than the applicable standard.
    (3) Deterioration factor for smoke. Deterioration factors for smoke 
are always additive, as described in paragraph (c)(1) of this section.
    (4) Deterioration factor for crankcase emissions. If your engine 
vents crankcase emissions to the exhaust or to the atmosphere, you must 
account for crankcase emission deterioration, using good engineering 
judgment. You may use separate deterioration factors for crankcase 
emissions of each pollutant (either multiplicative or additive) or 
include the effects in combined deterioration factors that include 
exhaust and crankcase emissions together for each pollutant.
    (d) Collect emission data using measurements to one more decimal 
place than the applicable standard. Apply the deterioration factor to 
the official emission result, as described in paragraph (c) of this 
section, then round the adjusted figure to the same number of decimal 
places as the emission standard. Compare the rounded emission levels to 
the emission standard for each emission-data engine. In the case of 
NOX+NMHC standards, apply the deterioration factor to each 
pollutant and then add the results before rounding.
    (e) For engines subject to NMHC standards, you may base compliance 
on total hydrocarbon (THC) emissions. Indicate in your application for 
certification if you are using this option. If you do, measure THC 
emissions and calculate NMHC emissions as 98 percent of THC emissions, 
as shown in the following equation:

NMHC = (0.98) x (THC).