Have you ever worn an SCBA in temperatures below freezing?  Are any of your SCBA's (or any SARs) stored outside in freezing temperatures? If you answered YES to either of these questions and you have never heard the phrase "Low Temperature Operation Instructions", you may want to sit down before reading further.  You will not find any specific OSHA requirements on these "Low Temperature Operation Instructions", but don't think for a minute that OSHA can not cite an employer when PPE is used outside the conditions prescribed by the manufacturer.  In particular I want to bring to your attention the use and storage of Self-Contained Breathing Apparatus (SCBA) in freezing temperatures.  ALL of the major brands that I have used and trusted have what they call "Low Temperature Operation Instructions" and it is CRITICAL that we abide by these instructions when using the SCBA in temperatures BELOW FREEZING (32ºF/0ºC).  To give you a flavor of what is REQUIRED, answer this question... Does NIOSH ever REQUIRE the use of a "nose cup assembly" for a respirator to be "NIOSH Approved"?

Although most of our clients prefer we not get this detailed in our auditing, it is our opinion this is easily within OSHA's scope of 1910.134(d)(1)(ii) or 1910.134(h)(2)(ii)(C).  I am not aware of OSHA ever issuing a citation for not following the manufacturer's "Low Temperature Operation Instructions"; however, let one of these units fail during their use because they froze up and this results in an injury/fatality or employee complaint and we have pretty much sunk our boat before they even arrive on site.  In the bigger picture, OSHA should always be the LEAST of our worries when we are dealing with our Respiratory Protection; and when we are talking about our SCBA failing in potentially IDLH atmospheres we NEED TO TAKE CARE of business before we worry about "compliance!  In other words, this issue is more about SAFETY than meeting some compliance requirements.  Here are some tips/recommendations for "Low Temperature Operation Instructions", but PLEASE refer to your owners manual(s) of your brands, models, styles of SCBA's that you may be using, as each manufacturer has different requirements.

Most respirators that are NIOSH approved are approved for use in temperatures to –25°F/-32°C; however, for temperatures below 32°F/0°C, NIOSH approval requires the use of a Nose Cup Assembly in the facepiece (PLEASE NOTE this is a NIOSH requirement for certification). Respirators intended for routine use and respirators not routinely used but kept for emergency use should be located in areas where the temperature is maintained ABOVE freezing (32 °F / 0 °C). Where it is expected that the respirator will be used in ambient temperatures near or below freezing, the respirator shall be equipped with a Nose cup Assembly to reduce the formation of vision impairing mist or ice on the interior of the facepiece vision area. If a respirator may be unavoidably kept at a temperature below freezing before the next use, special care MUST be exercised to be certain that all components of the respirator are THOROUGHLY DRIED after cleaning and BEFORE storage. Whenever use of the respirator is anticipated in areas at or below freezing, the facepiece, regulator, and connection hoses MUST be protected against exposure to water during storage. If a respirator must be kept at a temperature below freezing and it is not possible to bring it to room temperature before it is used, do NOT exhale into the facepiece until the facepiece is completely donned and properly fitted against the face.

The official "warnings" in my SCOTT user manual....

WARNING!! USE OF THIS RESPIRATOR IN TEMPERATURES AT OR BELOW FREEZING, 32°F/0°C, WITHOUT FOLLOWING THE LOW TEMPERATURE OPERATION INSTRUCTIONS MAY RESULT IN OBSCURED VISION DUE TO FOGGING AND/OR PARTIAL OR COMPLETE BLOCKAGE OF THE AIRFLOW. IF THIS SHOULD OCCUR, THE AIR SUPPLY MAY BE PARTIALLY OR COMPLETELY CUT OFF AND/OR IT MAY BE DIFFICULT OR IMPOSSIBLE TO SEE THROUGH THE FACEPIECE LENS WHICH COULD RESULT IN SERIOUS INJURY OR DEATH.

WARNING!! THE RESPIRATOR MUST BE COMPLETELY DRY BEFORE AND DURING STORAGE.   MOISTURE IN THE FACEPIECE OR THE WORKING PARTS OF THE RESPIRATOR, ESPECIALLY WHEN EXPOSED TO FREEZING TEMPERATURES, MAY CAUSE FOGGING OF THE FACEPIECE OR A MALFUNCTION OF THE RESPIRATOR WHICH COULD RESULT IN SERIOUS INJURY OR DEATH.

Folks this is a SERIOUS MATTER that often goes un-noticed by many users.  I learned about this the HARD WAY while fighting a house fire one winter in the early 1990's.  My SCBA froze up and I lost nearly ALL air-flow in extreme conditions and barely made it out of the house.  We originally thought that fire fighting water had gotten into the unit somehow and froze.  But the manufacturer opened an investigation and found that many of our units were icing up due to our inability to follow their "Low Temperature Operation Instructions".   So take heed to these instructions as a life may depend on it.