I believe it used to be the case that the blue fluid was formaldehyde based, but that may have changed. The green was supposed to be non formaldehyde, but probably was just as harmful in a different way.
Having worked in the North Sea you could look at pollution in 2 different ways. A heavily toxic chemical that only lasted a very short while before disappearing, or a milder one which took much longer to be effective, and therefore was hazardous longer.
Some of the so called 'green' chemicals are found to be even more nasty than the ones they are supposed to replace.