90% male crew: Can we substitute urinals for some toilets?

Yes, a standalone portable urinal counts toward the urinal side of the rule. OSHA 1926.51 asks for urinals, not urinals mounted inside a toilet unit, so a freestanding one on level ground next to your cluster is fine.

Two things to check before you rent it though. First, read Table D-1 the way an inspector will: one seat and one urinal per 40 workers means 60 guys rounds up to 2 urinals, not 1. Second, look inside your four standard units. Most of the ones I have had on my sites came with a small wall urinal next to the seat, and those count. If yours have them, you are already covered and the extra rental is just for convenience.

Also skip the idea of swapping out seats for urinals. The note in 1926.51 only lets you trade toilet seats for urinals when women will not be using the facilities, and you said almost all men, so keep your four seats where they are.

On a crew your size a separate urinal does take pressure off the seats at lunch and break times, so it is not a waste either way.

Yes, OSHA 1926.51 allows a standalone portable urinal to satisfy the urinal requirement. The standard requires one toilet seat and one urinal per 40 workers for crews of 20 to 199. You have four standard units providing four toilet seats for 60 workers. Adding one portable urinal meets the full requirement.

Place the urinal adjacent to your existing cluster on level ground with clear truck access for servicing. The service truck will pump both the standard units and the urinal during the same visit. Weekly service is typical, but high use may require more frequent visits.

Using a urinal instead of a fifth standard unit saves space and reduces rental costs. Confirm with your rental company that the urinal model meets OSHA compliance. Ensure the urinal has a holding tank and deodorizer like a standard unit. This setup is common on male-dominated construction sites.