PCB – Safety Considerations When Making PCBs


I've been making a few hobbyist PCBs at home and note that the photoresist developer and ferric chloride etch solutions are both pretty nasty chemicals that come with all kinds of warnings.

So I've been extremely careful

  • Wearing safety goggles while dealing with them.
  • Wearing disposable gloves at all times and throwing them away afterwards.
  • Wearing old heavy clothes so that a splash won't immediately touch skin.
  • Rinsing everything with large amounts of water afterwards.

My question is just how much of this is needed and how "nasty" are the chemicals?

I shall continue to wear goggles as they are no trouble and there seems no point risking eye damage however unlikely.

But what about the rest? If I get a single drop of the photoresist developer or feric chloride on me (and wash it off quickly) is that likely to be a huge problem? If I've rinsed something badly and there is still a trace of diluted chemical on there is that harmful? For example I'm throwing away my disposable gloves every time. I don't believe I get significant amounts of either on there but I'm not taking any risks. I could always wash them and use them again but they are cheap so I don't. But what risk is there that a few drops were on there and didn't get entirely removed by washing and they touched my skin?

I'm of course not looking for someone to say go ahead, it's fine 🙂 I'm just looking to know what the risks actually are so I can be an appropriate level of careful rather than over the top careful which I am now, which frankly can be a pain.

Best Answer

The developer is simply a dilute alkali, I use 12g of NaOH in a litre of water. It's quite safe but don't get it in your eyes and wash it off if you get it on the skin. Ferric chloride is quite safe, just wash it off if it gets on the skin. I always wear rubber gloves, both for protection and so that I can use hot etchant with manual agitation (I put the etchant and board in a small container in an old washing-up bowl with about 1" of just boiled water in it).

I've been making my own PCBs at home for about 40 years, using ferric chloride mostly. The only accident I've had that could have been serious was when I was walking across the room with an open bottle of conc. HCl in my hand, tripped, and a little splashed on my face next to an eye. I thought it might have got in the eye, but the fumes were bad enough. I immediately put my face under a tap and flushed the eye out for several minutes. It was sore for a few hours, but there was no damage.