gainer said:
I guess I'll have to try it again. Aside from the fact that the hydroxide in Rodinal is potassium, which is just as nasty as the sodium, it is nearly neutralized in Rodinal by the bisulfite and the HCl. Certainly the solution heats up while dissolving the hydroxide, but it's not so bad if you use ice cold distilled water as the solvent, and add the hydroxide slowly so as to avoid localized boiling. I've never heard of a concentrated solution of sodium or potassium hydroxide being volatile at room temperature, but reaction with some impurities in the water, or heat of solution might produce some undesirable results. Always add the caustic to the water, and slowly. Lye has been used as drain cleaner for as long as we have had drains to clog.
O.K. people. Ive used concentrated KOH (50%) and solid to make electrolyte for (et c.) and can assure you that it is NOT toxic unless ingested. I have been virtually swimming in the stuff without permanent effects. There are problems and hazards associated with its use.
Mixing materials can create a mist (particulate, not vapor) which, if inhaled, can cause serious nose, throat, and lung irritation. It is a choking experience that can leave one dissipated and with serious after effects such as pneumonia. USE BREATHING PROTECTION! Those stupid painting masks sold in hardware stores will help but one would do well to invest in a better one for many applications.
Caustic spray in the eyes is really miserable and can cause serious permanent damage. NEVER handle caustic(s) without eye protection. Again, those cheap goggles sold in hardwares will suffice.
If one is exposed to a spill, get water onto the effected areas ASAP. Remove clothing and get into a shower quickly. Conc. Caustic will dissolve hair quickly (I know). Vinegar will neutralize caustic. We used good ol dilute boric acid in buckets for this purpose and they were used regularly mainly on hands.
Lastly, I would advise care in handling any and all chemicals. One never knows when a misstep will occur (Murphys Law) but as far as KOH, NaOH, NaCO3, et c. are concerned, there is no real environmental hazard as the stuff will quickly break down in nature into benign materials.