A value over 800ppm indicated by an amber light should be seen as an indicator of inadequate background ventilation and a need to increase the ventilation further.
Dylid ystyried bod gwerth uwchlaw 800ppm, a ddynodir gan olau oren, yn arwydd o lefelau awyru cefndir annigonol a bod angen cynyddu'r lefelau awyru ymhellach.