A gas cylinder monitoring system comprising a gas cylinder for receiving and distributing gas. A flow control valve is associated with the gas cylinder and operable to allow or prevent the flow of gas from the cylinder. A monitor is provided for monitoring a signal from an input device associated with the flow control valve. The monitor has an environmental parameter sensor for detecting the presence or absence of a selected environmental parameter in the vicinity of the cylinder. The environmental parameter sensor is connected to the monitor for transmitting an environmental status signal thereto. A removable cover is provided for covering both the flow control valve and the environmental parameter sensor such as to only allow access to the flow control valve when the cover is removed. A transmitter is also provided for transmitting a signal, obtained by the monitor from the input device, to a receiver.