Dyne Fire Protection Labs started offering firefighting dry chemical agent testing earlier this year as requested by many of our customers looking to meet the International Maritime Organization (IMO) requirements for maintaining and inspecting their fire protection equipment and appliances per IMO 1432 (MSC.1/Circ. 1432 dated 31 May 2012).  In that document, subsection 8.2.4 under the 2 year requirements section, states to “test a sample of dry chemical powder for moisture content.”  To determine the moisture content, Dyne utilizes the procedure laid out in Annex E of the 2009 edition of EN 615 Fire Protection – Fire extinguishing media – Specifications for powders (other than class D powders) which calls for approximately 20 grams of the powder to be dried in a desiccator with sulfuric acid for 48 hours to determine the amount of moisture in the sample.  Dry chemical samples must maintain a moisture content level below 0.25% according to the 2009 edition of EN 615.

NFPA Requirements

The National Fire Protection Agency (NFPA) also has requirements on dry chemical agent testing as laid out in both the 2018 edition of NFPA 10 Standard for Portable Fire Extinguishers and the 2017 edition of NFPA 17 Standard for Dry Chemical Extinguishing Systems.

From the 2018 edition of NFPA 10: Topping Off. The remaining dry chemical in a discharged fire extinguisher shall be permitted to be re-used, provided that it is thoroughly checked for the proper type, contamination, and condition. Dry chemical found to be of the wrong type or contaminated shall not be re-used. Dry Chemical Agent Re-Use. The dry chemical agent shall be permitted to be re-used, provided a closed recovery system is used and the agent is stored in a sealed container to prevent contamination. Prior to re-use, the dry chemical shall be thoroughly checked for the proper type, contamination and condition. Where doubt exists with respect to the type, contamination, or condition of the dry chemical, the dry chemical shall be discarded.

From the 2017 edition of NFPA 17:

11.3 Maintenance

11.3.1 At least semiannually and after any system activation, maintenance shall be conducted in accordance with the manufacturer’s design, installation, and maintenance manual. As a minimum, such maintenance shall include the following:

(1) A check to see that the hazard has not changed

(2) An examination of all detectors, expellant gas container (s), agent container(s), releasing devices, piping, hose assemblies, nozzles, signals, and all auxiliary equipment

(3) Verification that the agent distribution piping is not obstructed

(4) Examination of the dry chemical (If there is evidence of caking, the dry chemical shall be discarded and the system shall be recharged in accordance with the manufacturer’s instructions.) Dry chemical in stored pressure systems shall not require semiannual examination but shall be examined at least every 6 years.


While there is no clear requirement to laboratory test for moisture content, NFPA 10’s and NFPA 17’s discuss examining the dry chemical for contamination, condition, and/or caking.  You could determine possible moisture contamination/caking visually to some extent but you could instead consider having the sample tested for moisture content against a published standard with clear pass/fail requirements. Dyne’s dry chemical test could take some of the guess work out of this process for you and provide you with a report to help you document you’ve met these requirements.  Note that Dyne does not ensure the proper type of dry chemical agent is being used, if dry chemical agent types have been mixed or determine all possible types of contamination.

As with our existing services, Dyne offers 5 business day guaranteed turnaround time, online reports, accurate and reliable results, and unparalleled customer service.  We also offer a free test kit for dry chemical samples which we highly recommend.  Each kit will be able to hold one dry chemical sample in a secure container that has been tested here at the lab to ensure it safely seals your sample from the environment preventing moisture pick up during transit.  Dyne will pay the shipping of these kits both to you and back to the lab within the lower continental United States.  For information on Dyne’s dry chemical services, check out the dry chemical testing information on our website, send an email to lab@dyneusa.com or give us a call at 800-632-2304.