A lot of the disadvantages with toilets are to do with the design. The universal design for a mixed sex can also be used for a single sex toilet and will be if the area in front is mixed sex.
Universal toilets in current building regs are suitable for being mixed sex, have a sink, are fully enclosed, sound resistant and have an easy mechanism to open the door from the outside outwards in order to access the room if anyone has collapsed stopping the door opening.
It sounds like the female and the male toilets are universal-like designs. When you have to compromise health and safety with these designs, the ways to lessen the risks are to have them in as busy a place as possible, opening directly out on to a place where lots of people are, particularly somewhere like a front desk where people clock who in going in and out, and to check them regularly. It helps to have as few as possible to keep an eye on and have cctv but if someone is having a medical emergency or is being assaulted, cctv is retrospective not preventative. Obviously I don’t like to focus on a particular case but to show the similarity and dangers - one man was left for 6 days in a toilet after a medical emergency in a council building.
The traditional unisex toilet in schools was typically put by the front entrance desk where it could be monitored.
What will happen if you turn a universal style female toilet into a mixed sex toilet by changing the sign on the door? It gives ‘permission’ for men to enter. It will become smellier and there will be more pathogens. This is not anti-men it’s just scientific fact. Men on average are not as hygienic. Their wee smells different as it consists of different components. We may not realise but studies show women and men can tell them apart! Guide dogs can smell the difference to direct their owners to the correct loo.
Men are possibly more likely to use the enclosed toilet for a ‘long sit down’. There are studies to show urine splashes and build up over time in men and women’s toilets and because men wee standing up, the particles travel further. Universal designs are the least healthy anyway as you can’t clean them as effectively and the ventilation is restricted as there’s no gaps for a mop or air flow. The door often rests in the closed position too.
The door handle is much more likely to be dirty as men do not wash their hands as much as women which is a problem as you touch it after you’ve washed your hands.
The ‘permission’ to be in there, also gives them the opportunity to set up hidden cameras. This sounds dramatic but is actually a very big and increasing problem which is always done by men (see Scottish Parliament).
Social ‘propriety’ goes out of the window with private designs in public spaces, particularly if they are mixed sex. They are places people have sex and do drugs. It does vary with location but it happens in schools, hospitals, restaurants, trains, planes, offices…I have examples of all of these. All of them involve one or more men.
Useful reference for hygiene:
https://salus.global/article-show/pathogen-findings-raise-concerns-about-move-to-unisex-hospital-facilities