Safety devices (including air bag inflators, air bag modules and seat-belt pretensioners etc.) may not be transported to, from or within the United States without prior approval by the appropriate authority of the United States (see US 1), Attention: Approvals and Permits Division (PHH-30). Such approval remains valid for subsequent transport provided there is no change in its composition, design or packaging. The dangerous goods transport document (shipping papers) must contain the EX number or product code for each approved safety device in association with the basic description required in 5;4.1.4. If product codes are used, they must be traceable to the specific EX number assigned to the safety device by the appropriate authority of the United States. The EX number or product code is not required to be marked on the outer package. Safety devices classified as Class 9 (UN 3268) in accordance with 49 CFR 173.166(b)(1) are not required to have an EX number assigned or have an EX number indicated on the transport documentation.