OSHA 1926.51: 45 workers, one porta potty and one urinal enough?
OSHA 1926.51(c) requires one toilet and one urinal for 40 workers, so 45 workers need one toilet and one urinal. You are compliant.
OSHA construction sanitation standard
The rule is 20 to 199 workers, one toilet seat and one urinal per 40 workers. Your 45 workers are above 40, so one toilet and one urinal meets the minimum. Mobile crews with transportation to nearby facilities are exempt, but if your crew is on site all day, you need the units.
Unit types and service
A standard portable toilet and a portable urinal are fine for an all-male crew. Weekly service visits are standard. In summer heat or with heavy use, you might need service twice a week to control odor and keep the paper stocked.
Placement and access
Put the units on level ground within 25 feet of where the vacuum truck can park. Make sure the path is clear on service day. If the truck can't reach, it's a missed service and you get billed for the trip.
Post your setup details if you want a check on service frequency or placement.