A compact wireless monitor for up to four gases. It provides continuous exposure monitoring of oxygen (O2), combustibles, and toxic gases, including hydrogen sulfide (H2S), carbon monoxide (CO), sulfur dioxide (SO2) and hydrogen cyanide (HCN) for workers and responders in hazardous environments. Wireless communications capability enables access to real-time instrument readings and alarm status (including man-down alarm) from any location for better visibility and faster response. Real-time hazard readings can also be communicated to the ProRAE Guardian Safety System and the EchoView Host Mini-Controller Closed-Loop Wireless System for safety-enhancing wireless monitoring.