30 CFR § 57.16016
Lift trucks.
Fork and other similar types of lift trucks shall be operated with the:
(a) Upright tilted back to steady and secure the load;
(b) Load in the upgrade position when ascending or descending grades
in excess of 10 percent;
(c) Load not raised or lowered enroute except for minor adjustments;
and
(d) Load-engaging device downgrade when traveling unloaded on all
grades.
For more information: See MSHA'S Program Policy Manual