It says on the Bold box we have not to use on silk or wool, so I don't. I didn't actually realise bold was bio as well though. It was just after a customer got in touch in the last day or so and explained a bit more about how she was washing her nappies over a long period of time and realised she was using bio, even washing nappies quite low most of the time, between 30-60 max. It's always advisable to wash any kind of wool with with wool safe washing powder / detergent and use a splodge of vinegar to restore a more wool friendly ph.
It's been quite odd though, of a handful of customers some people have had issues after very little use, some after lots of use. There's hasn't really been a pattern to it and I think it's down to washing patterns / machines / detergents. The enzymes in bio will eat away at wool and silk. Non bio isn't great either though as has a high ph so I can see if there was any build up that wouldn't be good either.
Wool likes a ph of 5-6, so slightly alkali. Washing powders are high at an alkali at 10-11 ish. I was looking into that before as I have a wool cotton blend wrap I want to dye, but can't use soda ash at a ph of 10-11, need to dye at a lower ph with baking soda, as wool can handle up to about a ph of 8.5-9 max. Fairly liquid is also about a ph 9. You can netralise a slightly higher ph by using vinegar as that's what I was planning to do to dye a cotton / wool blend.