well, it's no problem if you handle it properly, but it can lead to very nasty damage if there's one moment of lack of attention, which is not something that is the case with 99% other other chemicals we usually use as photochemistry.
for those who don't mind, it's worth to at least pointing out the risks. from wikipedia:
"Like other corrosive acids and alkalis, a few drops of sodium hydroxide solutions can readily decompose proteins and lipids in living tissues via amide hydrolysis and ester hydrolysis, which consequently cause chemical burns and may induce permanent blindness upon contact with eyes.[1][2] Solid alkali can also express its corrosive nature if there is water, such as water vapor. Thus, protective equipment, like rubber gloves, safety clothing and eye protection, should always be used when handling this chemical or its solutions. The standard first aid measures for alkali spills on the skin is, as for other corrosives, irrigation with large quantities of water. Washing is continued for at least ten to fifteen minutes.
Moreover, dissolution of sodium hydroxide is highly exothermic, and the resulting heat may cause heat burns or ignite flammables. It also produces heat when reacted with acids."
PS: I handled quite a bit of Sodium Hydroxide when necessary for special purposes, but using it to synthesise Sodium Metaborate only to save a few bucks is not appealing to me to say the least.
And the fact that it's sold as a drain cleaner without proper warning seems crazy to me, even more so considering that it's probably stored where kids can easily reach it.
Last edited: