In plain English
FAR 52.250-2, SAFETY Act Coverage Not Applicable, is a solicitation provision prescribed at FAR 50.206(a), most recently dated Feb 2009. The complete official text is reproduced below, verbatim, from GSA's published FAR source files.
Its text contains no sentence requiring insertion into subcontracts; see the flowdown section below for what that does and does not mean.
Does it flow down to subcontracts?
No flowdown mandate found in the clause text
This is a solicitation provision — it applies to offerors when submitting an offer, not to contract performance, so subcontract flowdown is generally not the operative question for it.
Where it's prescribed
As prescribed in 50.206(a), insert the following provision:
Prescribing reference: FAR 50.206(a).
The official text, verbatim
As prescribed in 50.206(a), insert the following provision:
SAFETY Act Coverage Not Applicable (Feb 2009)
The Government has determined that for purposes of this solicitation the product(s) or service(s) being acquired by this action are neither presumptively nor actually entitled to a pre-determination that the products or services are qualified anti-terrorism technologies as that term is defined by the Support Anti-terrorism by Fostering Effective Technologies Act of 2002 (SAFETY Act), 6 U.S.C. 441-444. This determination does not prevent sellers of technologies from applying for SAFETY Act protections in other contexts. Proposals in which either acceptance or pricing is made contingent upon SAFETY Act designation as a qualified anti-terrorism technology or SAFETY Act certification as an approved product for homeland security of the proposed product or service will not be considered for award. See Federal Acquisition Regulation subpart 50.2.
(End of provision)