“ The term "duty involving the servicing of aircraft or missiles with highly toxic fuels or propellants" shall be construed to mean duty performed by members as a primary duty that requires (1) removal, replacement, and servicing of the emergency power unit of an aircraft with H-70 propellant (30 percent water, 70 percent hydrazine) ; (2) participation by those personnel performing duties in (g) (1) who must also participate in an emergency response force, spill containment, or spill cleanup involving H-70 propellant (30 percent water, 70 percent hydrazinc) ”

“ No member shall be entitled, however, to receive the pay provided for in this subsection if, during any month or portion thereof, he is also eligible to receive incentive pay for other hazardous duty under the provisions of Section 301 of Title 37, United States Code. ”