NFPA 99 The New 2024 Edition O2 Alarms On Combo Vacuum / WAGD Systems

  • Wednesday, November 01, 2023 1:18 PM
    Message # 13274294
    Al Moon (Administrator)



    This new requirement is based around the existing need for this type of system,

    to maintained below an oxygen percent of 23.6%.

    So what are the new code items?

    • 1)    An oxygen monitor
    • 2)    Alarm signals at both master alarm panels

                                                Review  Section # parts # 1,2 a&b and 3


    I see a loophole in reading part #2 (a)

    If the medical vacuum pump complies with Section #

    This oxygen monitor and master alarm signal are NOT required.

    Section # has two parts.

    • 1)    Compliant with section #

    (i.e. as a whole to be deemed suitable by the manufacturer for materials)

    2) Designed of material and using lubricants and sealants that are inter in the presence of oxygen, nitrous oxide, and halogenated anesthetics.


    • 1)    Water sealed liquid-ring should be OK right?
    • 2)    Rotary Dry Claw Pumps Only Have A Gear Oil.              ? Is it also, ok ?

  • Sunday, November 12, 2023 9:15 AM
    Reply # 13278462 on 13274294

    Ref:, my understanding is that if a Rotary Dry Claw style pump in combined use utilizes a hydrocarbon free lubricant in the gear case, it doesn't require monitoring and mitigation. If the pump uses a conventional (naphthenic base) oil, it would require a monitor and mitigation device.

    P.S. Did anyone notice that (2) (b) states " Oxygen concentration exceeds 23.6%", and the definition of enriched Oxygen in 3.3.142 states " exceeds 23.5%"?

  • Saturday, November 18, 2023 8:46 AM
    Reply # 13281127 on 13274294
    Al Moon (Administrator)

    Regrading the concerns for this phenomena. That drove the NFPA 99 to listed the requirement to install and monitor / alarm for an oxygen levels > 23.6%.

    What type scientific studies and / or the research method was used ?


  • Tuesday, June 25, 2024 7:48 PM
    Reply # 13374550 on 13274294

    Issues with pure wick incontinent devices and hospital vacuum systems

    Over the course of the past year we have seen various concerns with hospitals medical/surgical vacuum systems here in the state of Hawaii.

    We have noticed intermittently low vacuum throughout the hospitals especially at night and vacuum pumps working harder than normal to supply vacuum to the facility with additional run times.

    With investigation we have determined that a new patient care product called “PureWick” has been introduced for staff and patient comfort that uses a high demand of vacuum.

    The demand has caused low vacuum in the hospitals as well as affecting suction units and in particular intermittent vacuum regulators to malfunction due to low vacuum.

    Vacuum source equipment and piping size was never calculated for this additional type of demand.

    In addition urine has ammonia in it. With ammonia even a little moisture will react with copper, brass and zinc and corrode them.

    At present time until further study of this system has been accomplish we recommend that the hospitals use the entire pure wick urine collection system rather than using the hospital vacuum system.

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