A fire is a risk in your environmental management system (EMS). Also, fire is an environmental aspect under abnormal situations.
So, you determine fire as a possible environmental aspect. Is there any mandatory prevention and or response preparation under your organization’s compliance obligations?
Even without any compliance obligations, your EMS should evaluate the significance of that environmental aspect and its impacts. If it is deemed to be significant you should consider ISO 14001:2015 clause 8.2 and prevent and or prepare a response to a possible fire in your facilities.