ATLANTA – It’s odorless, colorless and deadly. And if carbon monoxide is leaking in a school, it might not be detected until people are ill.

A leak at an Atlanta elementary school that sent 42 students and seven adults to hospitals had school officials considering whether to install carbon monoxide detectors, a possibly life-saving move that is only required in a handful of states. The detectors are not required in schools by law in Georgia and other states. Connecticut requires them in schools, while Maryland requires them in newly built and remodeled schools. Building codes and local rules can require them in schools elsewhere. When properly installed, the detectors give a warning when carbon monoxide reaches unsafe levels.

“To me, it’s somewhat of a no-brainer in the sense that you’ve got fire alarms,” said Doug Farquhar, program director for environmental health at the National Conference of State Legislatures. “There’s no school in the country that’s going to open unless there’s a fire alarm system. Why not add carbon monoxide?”