[Code of Federal Regulations]
[Title 40, Volume 18]
[Revised as of July 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR90.118]

[Page 186-187]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 90--CONTROL OF EMISSIONS FROM NONROAD SPARK-IGNITION ENGINES AT OR 
BELOW 19 KILOWATTS--Table of Contents
 
       Subpart B--Emission Standards and Certification Provisions
 
Sec. 90.118  Certification procedure--service accumulation and usage of 
deterioration factors.

    (a)(1) The test engine must be operated with all emission control 
systems operating properly for a period sufficient to stabilize 
emissions.
    (2) The period sufficient to stabilize emissions may not exceed 12 
hours.
    (b) No maintenance, other than recommended lubrication and filter 
changes, may be performed during service accumulation without the 
Administrator's approval.
    (c) Service accumulation is to be performed in a manner using good 
engineering judgment to ensure that emissions are representative of 
production engines.
    (d) The manufacturer must maintain, and provide to the Administrator 
if requested, records stating the rationale for selecting a service 
accumulation period less than 12 hours and records describing the method 
used to accumulate hours on the test engine(s).
    (e) For purposes of establishing whether Phase 2 engines comply with 
applicable exhaust emission standards or FELs, the test results for each 
regulated pollutant as measured pursuant

[[Page 187]]

to Sec. 90.119 shall be multiplied by the applicable df determined under 
Sec. 90.104 (g) or (h). The product of the two numbers shall be rounded 
to the same number of decimal places contained in the applicable 
standard, and compared against the applicable standard or FEL, as 
appropriate.

[60 FR 34598, July 3, 1995, as amended at 61 FR 20742, May 8, 1996; 64 
FR 15239, Mar. 30, 1999]