The least toxic working soluiton may be PC-TEA. It contains phenidone, ascorbic acid (vitamin C) and triethanolamine (TEA). TEA can be mixed safely with the other chemicals in a water bath. Once diluted 1:50 for use it contains all three chemicals in very small quantities. There is no metol and there isn't even any sodium sulfite. Stop bath can be plain water or a mixture of water and citric acid. Whether you use a sodium thiosulfate or amonium thiosulfate fixer, it needs to be treated with some respect.