Has anyone but me ever heard of the debate between Blue Cobalt Dichloride Dye vs. Gold Phenolphthalein Dye for use in Desiccant filter/breathers?

Quote the Air Sentry web site:

"In July, 2000, the responsible authorities in the European Union implemented Directives 98/98 EC and 67/548 EEC. These directives classified Cobalt Dichloride, and any substances that contain Cobalt Dichloride, as a class 2 carcinogen, which is “Toxic” and “Dangerous to the Environment”. Substances classified in this manner require the display of certain warning labels on the container of the substance. These warning labels even included, in some countries, a skull and crossbones."

"Both Cobalt Dichloride and Phenolphthalein are chemicals, and no chemical is perfectly safe, however, “Phenolphthalein is considered to present a much lower degree of hazard than Cobalt Dichloride”."

Scare tactic or valid?

Terry O

I sthat official? Should we update our chemcical handling procedure?

Can you explain what the dye has to do with the breather?

Is it the blue stuff that turns red when getting moisture?

Sorry it took so long to post a follow up - have been on the road too much this last month!

This is the link where the original details were posted:

Summary of Silica Gel Dye Debate and Facts

Terry O

If it is the (blue) silica gel, I know, this item is wide spread in the industry (not only for air dryers).
You can find it in small paper/cloth envelopes in computers / shoes etc..

The debate is about the safety of the blue versus the gold.

I guess it is not much of a debate as no one seems to have concerns.

Terry O

Line 120 Verify dessicant cartridge. If it has change to blue, replace it.

Blue??? It is gold!!!

The dessicant we use in the air dryer is the gold type.
The blue one is still there, on top in a small bowl, put more as an visual aid. If it turns pink too much, you have to dry it and take the moisture out. Just put it in the microwave!! It will turn blue again.
I did it because the question arised why the gold one was replaced, but the blue indicator was "forgotten" by maintenance.

The gold one is not reusable, I always wondered why the gold was used. Probably "marketing forces", the vendors also have to live.


In my student time I had a bottle of it near the computer, every three months I dried it in the oven and I had simple humidity indicator.