As an industrial hygienist that used a personal Beowulf cluster during graduate studies in chemistry, I found the recent discussion on immersion cooling doubly interesting. Is an immersion coolant bath a dip tank according to US OSHA regulations? The two potentially relevant ways for such use to be considered a dip tank would be if the immersion bath is considered to either "alter the surface of an object" or "change the character of an object". Ultimately, it would be up to the OSHA Inspector and associated legal team to decide whether they wanted to pursue temperature change as meeting one of these criteria.
If it is determined that an immersion bath is a dip tank, then there are some specific requirements for liquids with a flashpoint. All liquids with a flashpoint of less than 200 F are covered by these requirements, liquids with a flashpoint greater than 200 F are covered by these special requirements (OSHA Standard 1910.125) if "the liquid is heated as part of the operation". So, pretty much any liquid used as an immersion coolant that has a flashpoint would be covered, as the whole purpose of the setup is to heat the liquid (and then subsequently cool it). The major elements of this specific standard is that a fire suppression system or a lid that can be operated manually and that automatically closes in the event of a fire be installed if the tank contains more than 150 gallons of flammable liquids (remember, OSHA considers any liquid with a flashpoint to be a flammable liquid now) or has a liquid surface area of more than 4 square feet. The other element of concern is that a liquid with a flashpoint used in a dip tank may not be heated to the boiling point (regardless of the size of the dip tank). Do the phase change liquids have flashpoints? There are some other regulations involving overflow piping and drainage dependent on the size of the dip tank. Happy, and safe, computing! _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin Computing To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
