43 CFR 28.3 - Emergency assistance.
In the absence of a reciprocal fire protection agreement, each agency head may provide emergency fire protection will not jeopardize the property of the United States by making it impossible for the agency head to protect the property of the United States and such assistance is determined to be in the best interest of the United States. The providing of emergency assistance shall not be in the best interest of the United States and may not be granted by an agency head if:
(a) Persons other than those currently employed by the agency at the time of the emergency and trained in the type of emergency assistance being provided would be used in the providing of the emergency assistance.
(b) Assistance is provided to a place more than an hour's travel from where the agency maintains fire protection facilities. Assistance which requires more than an hour's travel may be given for those fire emergencies threatening to last more than 12 hours, or endangering human life.