From ANSI/ITSDF B56.1-2012 4.17.3(o) "The combined weight of the platform, load, and personnel is not to exceed one-half of the capacity as indicated on the nameplate of the truck on which the platform is used."
Check the data plate of the truck you are using, this shouldn't be an issue with our maintenance platforms, each has a capacity of the platform listed, max 1,000 lbs, so the combined weight of the personnel and their cargo added under 500 lbs means even the smallest warehouse truck should be okay. Best to check regardless.