Section 312(f) of EPCRA states that "upon request to an owner or operator of a facility which files an inventory form under this section by the fire department with jurisdiction over the facility, the owner or operator of the facility shall allow the fire department to conduct an onsite inspection of the facility, and shall provide to the fire department specific location information on hazardous chemicals at the facility."  Can the fire department request an on-site inspection of a facility which does not file an inventory form under Section 312 since the chemicals present at the facility are below the threshold?

Yes.  Section 312(e)(1) permits the fire department with jurisdiction over the facility to request that the owner or operator of the facility provide Tier II information concerning the facility.  When a fire department requests Tier II information pursuant to Section 312(e)(1), the applicable threshold for the facility subject to the request is zero (40 CFR §370.10(b)).  Therefore, upon a fire department's request, the facility would have to file Tier II forms.  Because the owner or operator of the facility would be required to file a Tier II form, the owner or operator must allow the fire department to conduct an on-site inspection of a facility that has not previously filed.