EPA only partly agreed to a petition submitted by Earthjustice and over 100 other NGOs who basically went on a fishing expedition for TSCA information on any chemicals that could be used in hydraulic fracturing. Yes, they will start looking at rulemaking to gather information on the use of chemicals fracking under 8(a) and 8(d), but they want to be narrower than all chemical used in oil and gas exploration and production and don't want to duplicate information they already have access to. Likewise, testing under section 4 was not considered justified for the broad category of chemicals requested. See petition response here.
In general, EPA is only going to positively respond to narrow requests to use TSCA with a good deal of justification behind it. And even then, they offer to start rulemaking, with no guarantees of final rules.
Watch for the Advanced Notices of Proposed Rulemaking on 8(a) and (d) reporting rules on hydraulic fracturing chemicals.