work with good ventilation and ventilated workbenches. That formaldehyd is carcinogen is an old story. It's important to prohibit direct contact and inhalation of the fumes. In histology we deal mostly with diluted solutions.
There's a study in German, where under good working conditions, there's no danger because the dangerous airconcentrations are not reached.
Personal protection is the point!
Changing to other fixatives brings up other difficulties.