Sunday, January 5, 2014
Weekend Wonderings: Are bath melts safe for a baby? Why would we find sodium hydroxide in a lotion?
In this post Weekend Wonderings, Rosi asks: I just found the bath melt and I was wondering if it is suitable for babies because I would like to make some and give away to a friend who will soon be a mom. My concern is the baking soda and citric acid.
When in doubt, leave it out. I really can't stress this enough. Baby's skin is sensitive because they haven't had time to develop all the great things our skin does for us, such as keeping things out or being able to respond quickly when irritated or injured, and I think it's always wise to put as little on or near babies as possible. I don't think the bath melt will be harmful for the baby, to be honest, but I'd rather be safe than sorry. Why not make some bath melts without baking soda and citric acid instead?
As for mom, it's fine for her skin!
As a note, I have a series on babies' and children's skin coming up shortly. It's really quite a fascinating topic!
In this post, What do you want to know? Making toner with quats, Rosi asks: I have some body lotion from the store and there is sodium hydroxide on the ingredient list, what does it bring to the lotion?
Sodium hydroxide could do one of three things in a lotion...
1. It could help the carbomer turn into a gel;
2. It could be helping adjust the pH to a more alkaline one; or
3. It could be turning something into a soap to behave as an emulsifier.
To turn a carbomer turn into a gel, we use an alkaline ingredient - in this case it would be something like an 18% solution of sodium hydroxide - to turn it from the flaky gel stuff into the gooey gel stuff. To adjust the pH, we would use a dilute solution of sodium hydroxide to raise the pH to become more alkaline. To use it as a soap as an emulsifier, we would be turning an oil or triglyceride into a soap through the process of saponification. (I know very little about this concept, to be honest...)
Chemistry Thursday: Chemical reactions
Gels: Formulating eye gels - more ideas (loads of links in this post on gels)