What it is
STANAG 3943 is the NATO Standardization Agreement covering the physiological requirements for aircrew CBRN (chemical, biological, radiological and nuclear) defence assemblies used in flight. This is Edition 4, promulgated 17 July 2018, superseding an earlier STANAG 3943, Edition 3.
A STANAG is not the specification
A STANAG is the agreement by which NATO nations commit to implement a standard, not the technical specification itself. STANAG 3943's own text is short and administrative: an aim, a single interoperability requirement, the standard it names, and the ratification, review and reporting machinery. The physiological requirements for the protective assemblies themselves are specified in a separate publication, AAMedP-1.16 Edition A, which the STANAG names as the standard participating nations "agree to implement." Anyone actually designing, specifying or checking that equipment needs AAMedP-1.16's own text, not this cover agreement.
What it commits nations to
The stated interoperability requirement is "to standardize the physiological requirements for aircrew CBRN defense assemblies used in flight in order to facilitate the exchange of comparable information between nations and enhance interoperability." Nations are encouraged to carry the agreement into their own doctrine, procurement and contracts, so the point where it actually bites is wherever one of those documents references it, not a single fixed date.
Who it binds, and how
STANAG 3943 binds nations, not suppliers. It becomes binding on a given nation through ratification, which NATO records in the NATO Standardization Document Database (NSDD): national decisions on ratification and implementation "are provided to the NSO," and the STANAG "is considered implemented when a nation has issued the necessary orders/instructions putting the details of the agreement into effect." Nations are invited to report their effective implementation using the form in Annex H to AAP-03(J), and partner nations report adoption using the form in Annex G to AAP-03(J). The agreement is supervised under the Military Committee Air Standardization Board (MCASB) and its Aeromedical Working Group. A supplier meets STANAG 3943, or the AAMedP-1.16 requirements it covers, only where a contract or tender says so - the document itself sets no obligation reaching a supplier directly.
How it's evaluated
STANAG 3943 describes no certification scheme and no audit. What it describes is nations reporting their ratification and implementation decisions to the NSO for the record; nobody is "STANAG 3943 certified," and the document never uses that language. Where a supplier's CBRN protective-assembly work does get checked against AAMedP-1.16's requirements - specifications, test records, inspection evidence - the assessor and the evidence required are set by the contract's own quality clause, not by this STANAG.
Standards it references
STANAG 3943 covers AAMedP-1.16, the Allied Medical Publication that carries the actual physiological requirements. Its "Other Related Documents" also list STANAG 3198, "Functional Requirements of Aircraft Oxygen Equipment and Pressure Suits," which in turn covers AAMedP-1.3. Reports on implementation and adoption of STANAG 3943 use forms in Annex H and Annex G to AAP-03.