Masks For Coolant Mist

Posted on Monday, March 28th, 2011 at 4:24 pm. Tweet

Masks For Coolant Mist

The questions come up again about masks to protect someone from the inhalation of coolant mist.

We get these because we build and sell filter systems. In order to build a decent filter system we did an awful lot of research. So we get questions from people that aren’t entirely related to what we do but we try and answer them anyway.

Any mask will help. However I do not consider masks to be an ideal solution for several reasons. 1.  Masks must be close-fitting. If you have a gap around the edges then you lose a great deal of the effectiveness of the mask.  2.  The mask will eventually become saturated with coolant and you’ll be inhaling coolant mist from the mask   3. The masks are very uncomfortable to wear and thus there is a strong tendency to not wear them at all. The only truly effective mask is a full face respirator was supplied air which is expensive, requires custom fitting and is even more uncomfortable than the paper masks.

As I said, these are my opinions. When I bought the new building I spent the money required for proper ventilation and collection so that we don’t have to wear masks any more.

I have done collection with something as simple as a bathroom exhaust fan and flex duct.  We have an old rotary sandblaster where we do dust collection with a shop vac whose hose is duct taped to the vent on the sandblaster.

Coolant becomes mist because the coolant is energized. If you trap the mist someplace where it can calm down it will collect and turn back into coolant.

Occasionally you hear a concern about coolant burning or coolant mist exploding.  It is true that some finely divided materials will explode but these are things such as wood dust or wheat dust. These are dry and flammable. When finely divided and then ignited they burn very, very rapidly which is pretty well one definition of an explosion.

By contrast many coolants are water-based and, when mixed properly are about 85% to 95% water.

Straight oil coolants do not mist which is one of their primary benefits.

In a temporary operation we use Shop Vacs as collectors.  Because of the noise, we do not recommend them as a permanent solution. However they do generate more than enough suction to draw the mist or fumes away from the operator.

We design our systems so that the fumes are drawn away from the operator. In some situations this means putting the collector on the side opposite the operator. In other situations it means putting the collector between the workstation and the operator.

For system design and testing we use RAE irritant smoke Part Number 10 – 123 – 01 from Rae systems Inc. 888-723-8823.

If you absolutely, have no other choice than a mask I would suggest using a face shield in front of your face.  The face shield would be your first and primary line of defense with the mask as a secondary line of defense.

The PK Safety website recommends changing a mask after eight hours if you are working with coolant mists.   http://www.pksafety.com/dustmasks.html

Were it I doing it I would certainly change masks more often than that.

The PK safety website also carries a broad range of 3M masks.

We have no affilaition with RAE or PK Safety.

Tags: Machine coolant