Abstract: An improved arterial syringe safety vent is dually optimized for needle safety and arterial blood degassing efficiency. The safety vent of the invention includes a housing, a needle lock to capture a needle, and a venting portion comprising a hydrophilic filter. The needle lock of the invention is adapted to lock a needle tip between a membrane and a venting potion to prevent accidental needle stick. In en exemplary embodiment the safety vent of the invention engages a needle capture device in a manner that allows movement of the housing in relation to the needle capture device so that the tip of a needle captured by the needle capture device can be locked in a position that prevents exposure of the needle tip. The safety vent of the invention is self-supporting to permit single-handed operation.