How to get rid of the white particles at the hinges and bottom of walk-in bath tub door?

Use white vinegar....get a rag sopping wet with the vinegar, put it over the area with the white particles. Leave on for about 8 hours, being sure it doesn't dry out. It should then easily wipe and rinse off. A toothbrush or wire brush should help loosen any leftover stubborn corrosion.

Spray them with WD40 or some other brand rust converter and the wipe the hinges and spray them with a silicon spray to oil them up and the door wil swing easier. the humidity is reacting with the hinges but the sprays will fix it. Ciao 4 now