[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: 40CFR90.109]

[Page 182]
 
                   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. 90.109  Requirement of certification--closed crankcase.

    (a) An engine's crankcase must be closed.
    (b) For purposes of this section, ``crankcase'' means the housing 
for the crankshaft and other related internal parts.
    (c) Notwithstanding paragraph (a) of this section, the Administrator 
will allow open crankcases for engines used exclusively to power 
snowthrowers based upon a manufacturer's demonstration that all 
applicable emission standards will be met by the engine for the 
combination of emissions from the crankcase, and exhaust emissions 
measured using the procedures in subpart E of this part. This 
demonstration may be made based upon best engineering judgment. Upon 
request of the Administrator, the manufacturer must provide an 
explanation of any procedure or methodology used to determine that the 
total CO emissions from the crankcase and the exhaust are below the 
applicable standard for CO.

[60 FR 34598, July 3, 1995, as amended at 61 FR 58301, Nov. 13, 1996]