Okla. Stat. tit. 47, § 6-110.1
The following endorsements shall be placed on an Oklahoma driver's license to any person qualifying therefor as determined by the Department of Public Safety.
Endorsement Authorizes the operation of:
"H" A nontank type vehicle used to transport hazardous materials in placardable amounts pursuant to 49 C.F.R., Part 172, subpartF; "M" A motorcycle; "N" A tank vehicle as defined in Section 1-173.1 of this title; "P" A vehicle designed by the manufacturer to transport sixteen or more passengers, including the driver; "T" A vehicle with double or triple trailers; "X" A tank vehicle used to transport hazardous materials in placardable amounts pursuant to 49 C.F.R., Part 172, subpart F.
The Department may also provide for additional endorsements as may be needed or as otherwise provided for by law.
All endorsements as provided for in this section must be obtained prior to the operation of such vehicles.
However, the requirement for a hazardous materials endorsement is not required for the operation of farm vehicles used to transport pesticides, fertilizers, or other products integral to farming, but which are defined as hazardous materials.
Laws 1990, c. 219, § 17, eff. Jan. 1, 1991; Laws 1991, c. 162, § 3, emerg. eff. May 7, 1991.