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If your wastewater environment is classified as hazardous (Class I, Div 1) due to flammable gases (e.g. an enclosed sewage wet well with methane or hydrogen sulfide buildup), you cannot use a regular float switch by itself connected to high current. In such cases, the float switch circuit must be intrinsically safe – meaning it’s designed so that it cannot release enough energy to ignite an explosive atmosphere. Practically, this is achieved by using an intrinsically safe barrier or control panel: the float connects to a special low-power module that limits current/voltage. The float itself can be a normal float (many floats are simple devices that can be used in IS circuits), but all wiring and devices must meet code. Sometimes manufacturers offer completely sealed explosion-proof floats, but more common is using standard floats with an intrinsically safe relay interface. In short, yes, for any classified hazardous location, use an approved control system that supports intrinsically safe float inputs.
Never wire a float carrying full pump voltage into a hazardous area sump without such protection – it’s both illegal and dangerous. Consult safety standards (NEC Article 500 etc.) and get a properly rated control panel for those scenarios. For non-hazardous locations (most outdoor or vented sumps), standard floats are fine.