The problem with trying to go 'green' is that some paint manufacturers want to convince you they are as dedicated as you are to improving the world we live in. They claim they have an eco friendly paint, they say it is non toxic and it has low or minimal VOC. Some even go as far as saying their paint is organic.
Without delving in to the details it's easy to get caught up in the marketing. That's the whole idea of course - they want you to think you are doing something positive by buying their products. So let's take a look at some of the things to be aware of.
Acrylics. Acrylic is basically a kind of plastic. It's a product of the petro-chemical industry - it comes from crude oil. Some will tell you acrylic is non toxic but even then, too much ends up in the water system or in landfill where it doesn't breakdown. There are loads of paint makers who tell you their paint is eco friendly because it is water-based rather than oil based. But a water based paint uses acrylic binders, it can also contain other unpleasant chemicals but as long as it is classified as low VOC it seems they are allowed to claim eco status. Don't be fooled - if someone tells you they are using eco friendly paint, ask them what's in it - ask them if it contains acrylic.
VOC. Volatile Organic Compounds are unstable compounds emitted from the paint in use and even when it has dried. Some of these elements can be detrimental to health, especially in people with existing conditions such as asthma. They can lead to dizziness and nausea. High levels can even be linked to cancer.
With that in mind, you can see why some companies sell you the idea of minimal VOC being much better for you. Most of the time that's true. However, there are some natural paints that include natural plant oils. These natural ingredients give off fumes that can be harmless. But because these oils are emitted from the paint they have to be classed as higher VOC. So higher VOC is not necessarily a bad thing. Confusing eh? So to simplify a little, synthetic VOCs are usually bad. Natural VOCs can be good. Auro use natural oils in some of their paint, it smells but it smells nice. It isn't low VOC - but in this case that's a good thing.
Additives. The problem with natural ingredients, just as in food, is that they can go off. A fully natural product without any kind of preservative will decay - even after it's on the wall bacteria can take over and create unpleasant smells. So paint needs to have additives to give it anti-bacterial properties. So there is sometimes a compromise to be made with natural paints and we may need to accept small amounts of synthetic chemicals in order to get the paint to do what it's meant to do.
In summary, a water-based paint isn't necessarily non-toxic or chemical free. A paint with higher VOC isnt necessarily toxic and bad for you. Check the ingredients listed on the tin or website. If there aren't any shown, ask the maker what's in the paint. If they won't tell you then maybe they are hiding the truth.