Randy, ELI5 formalin

[IrezumiHurts]

Per title @Randy Holmes-Farley Basically, what is it, in a relatable non chemist way of understanding?

For example, i can wrap my head around alcohol, basically a solvent i can use to clean things, dries quick, leaves behind (to my knowledge) relatively little residue and what's left is likely inert for all intents and purposes. Kills basically everything (i don't know how)

Then there's bleach. Again i understand it oxidizes things which has a purifying effect for lack of better words

I use formalin to treat all my fish. Safely of course. To me it's a wonder chemical for prophylaxis on intake, heading off things like brook and uronema almost entirely, and oh by the way reducing velvet ich and flukes populations on the fish. One treatment isn't enough but most importantly it buys me time to ramp up my other processes. But i am left lingering... what the heck is it? I understand it's a tissue fixative or whatever, i dissected frogs and lambs eyeballs in high school but really just an having a hard time understanding what it is and by what mechanism it is so effective on killing parasites?

Thank you

 

[Randy Holmes-Farley Verified Community Expert]

Formalin is formaldehyde in water. Formaldehyde reacts with tissues and can eventually kill parasites and other microorganisms by damaging various biomolecules that make up their bodies.

 

[IrezumiHurts]

Formalin is formaldehyde in water. Formaldehyde reacts with tissues and can eventually kill parasites and other microorganisms by damaging various biomolecules that make up their bodies.

Fair response. Thank you

Do you have any recommendations for safely cleaning used equipment or disposing of it? For example, if i use some nitrile gloves to handle a fish in dip, how should i go about cleaning the formalin off the gloves? I usually soak them in 1 to 200ppm bleach, but should i be concerned about some nasty reaction between the two? Does it just flash off like alcohol if i leave it outside?

Thank you for the follow up question

 

[Randy Holmes-Farley Verified Community Expert]

The formalin itself should was off easily. It is very water soluble. It will also evaporate, so an object rinsed well and then allowed to dry out should also all fit any small amount that penetrated plastic to disappear to the air.

Bleach and formaldehyde may react to produce formic acid (main ingredient in All for Reef) or carbon dioxide, but I don’t think that’s a big deal.