I'm looking into PCB etching,which requires ferric chloride
The issue is that where I live, only anhydrous ferric chloride is sold (Which is stupid. They don't even label it properly as anhydrous - got exposed to HCl fumes for 2-3 hours, thankfully the doctor found nothing abnormal with me and I got sent off with some anti allergy meds).
I've decided to switch to Sodium Persulphate following a discussion over here - https://www.eevblog.com/forum/beginners/etching-pcb-dealing-with-anhydrous-ferric-chloride/
What I'd like to know is if sodium persulphate is safe enough to be used at home without much ventilation?
Also, are there any decomposition issues I need to be aware of for a previous batch of the solution I made by adding anhydrous FeCl3 to tap water? (The mixture is in a plastic juice powder container and is 4-7 days old) I've heard this stuff can release chlorine gas and so I want to deal with it as cautiously as possible - maybe my worry is misplaced but it doesn't hurt to be cautious. I'm looking to dispose off these - both the 500gm jar I got off of Amazon as well as the mixed solution, unfortunately we Indians don't have much in the way of hazardous waste disposal - the only options I see are industry oriented and there's no way an individual like me could pay the fee for industrial waste disposal services. Either way, I'm looking to dispose this stuff away in as responsible a manner as possible.
Please keep in mind I will be using this etchant stuff at home. If you have any suggestions regarding alternatives, do mention them. If I can find it and it's safe enough, I will switch over to it.
If this isn't the proper place to ask these questions, please direct me to a place more suitable for these questions.