A first aid officer who is engaged to provide first aid services at a relevant workplace and who has a current certificate in the use of nitrous oxide (S4) granted by a registered training organisation may (a) possess nitrous oxide (S4); and(b) administer it, or supply it for self-administration, to a person on the oral instruction of a medical practitioner or paramedic; and(c) administer it, or supply it for self-administration, to a person on the written instruction, other than on a standing order, of a medical practitioner or paramedic; and(d) in an emergency, administer it, or supply it for self-administration, to a person without instruction from a medical practitioner or paramedic.