A single pin initiator including a header body forming an eyelet, a header lip surface and a connector shell. An initiator canister is connected to the header body and defines a first storage chamber, wherein a supply of initiation charge material is contained. A pin is positioned within the eyelet, with a pin head portion extending into the first storage chamber defined by the initiator canister. Electrical communication between the pin and the header body is provided by a bridgewire connected to the header body and preferably contacting a flat surface of the pin head portion. A supply of initiation pyrotechnic material is disposed on at least a portion of the bridgewire, and is in initiation communication with the supply of initiation charge material. Also disclosed is a passive restraint system assembly including the single pin initiator assembly of the present invention. The passive restraint system assembly includes a gas generant canister positioned over the initiator canister and securely connected to the header body, which defines a second storage chamber containing a supply of gas generant material.