The Phase I ESA 180-day rule: how long a Phase I is good for

Short answer: Under the Phase I ESA 180-day rule in 40 CFR 312.20, five parts (interviews, cleanup lien search, government records review, site visit and Environmental Professional’s declaration) must be done or updated within 180 days before you take title, and all work within one year. Both clocks run from the work dates, not the report date. SBA loans add a one-year test measured to the loan number date.

In practice, a Phase I is good as is for 180 days from the earliest of those five parts, and for up to one year from its oldest work if those five parts are updated. The rules below are as published in October 2026. To check your own dates, use the Phase I validity calculator.

What the Phase I ESA 180-day rule requires

The All Appropriate Inquiries (AAI) rule, 40 CFR Part 312, is the EPA regulation that defines the environmental inquiry a buyer must complete before acquiring a property to qualify for the landowner liability protections in the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), the federal Superfund law. A Phase I Environmental Site Assessment (ESA) performed to ASTM E1527-21, which section 312.11 recognizes as a way to meet the rule’s inquiry requirements, is the report that documents the Environmental Professional’s (EP’s) part of that inquiry. Section 312.20 sets two time limits:

Acquisition means the day you take title (40 CFR 312.10). EPA considered tying the clock to the purchase agreement instead and decided against it, noting that the period between signing and title transfer may be the most convenient time to get access to the property and do the work (70 FR 66083).

EPA’s reason for the one-year limit is in the 2005 rule’s preamble: “a year is sufficient time for conditions at a property to change” (70 FR 66083). For work between 180 days and one year old, “only certain aspects” must be refreshed (70 FR 66075), and those are the five in the table.

Some summaries, including EPA’s own AAI web page, list four time-sensitive parts and leave out the declaration. The regulation lists five, and so does E1527-21 (section 4.6.2). The fifth one matters in practice: an update is not complete until an EP signs a new declaration.

Which date starts each clock

Not the date on the cover. ASTM E1527-21 says the report date generally does not show when the individual parts were completed and should not be used to test either limit (section 4.6.3). A report is written after the work, so its date makes the work look younger than it is.

• The 180-day clock starts at the earliest of the five dates. All five must be inside the window, so the oldest one decides. E1527-21 requires the report to list the dates of the interviews, the government records review, the site visit and the declaration (section 4.6.1).
• The one-year clock starts at the oldest work in the whole inquiry. Section 312.20(a) applies the one-year limit to all of the inquiry, and E1527-21 says every other part must be done within one year (section 4.6.3). That includes historical research and your own inquiries, which can be older than the five dated parts.

Answers that count from the report date, or from the site visit alone, get this wrong. If the records review came before the site visit, counting from the site visit overstates the time left.

To find your dates:

1. Read the component dates the report lists for the interviews, records review, site visit and EP declaration.
2. Add the date of the cleanup lien search. It is your responsibility as the user, and E1527-21 requires the report to show its date only if you hired the EP to run it (section 4.6.1). If a title company ran it for you, use that date.
3. Note when the historical research was done (the date the aerial photographs, maps and directories were reviewed, not the years those sources show) and the dates of any earlier report the work builds on. For an updated report, the dates of any original work the update did not redo, such as historical research, still count toward the one-year limit.
4. If a date is missing, ask the consultant for it in writing before you rely on the report.

Does a Phase I expire? Its shelf life at closing

Neither the AAI rule nor ASTM E1527-21 sets a fixed expiration date for a Phase I. E1527-21 treats it as a question of the report’s continued viability (section 4.6). Whether the report still counts toward the landowner liability protections depends on how old its work is on the day you take title:

The regulation does not say how to count the days. Our calculator treats day 180 as the last day a report is usable as is, and the same calendar date one year after the oldest work as the last day an update can help. Do not plan a closing for either last day, because a one-day slip changes the answer.

The work must also be finished before title passes. EPA’s enforcement guidance says purchasers who want a landowner liability protection cannot perform all appropriate inquiries after acquiring the property (EPA Common Elements guidance, p. 5). A Phase I finished the week after closing does not count.

Worked example: one purchase, four closing dates

Take a warehouse purchase. The EP’s government records review and historical research are done on Monday, February 2, 2026, which makes that date both the oldest work in the inquiry and the earliest of the five parts. The site visit and interviews follow on February 9, the EP signs the declaration on February 13, and the buyer’s title company runs the lien search on February 17. Every count starts from February 2: the 180-day window ends Saturday, August 1, 2026, and the one-year limit ends Tuesday, February 2, 2027.

For the September closing, the buyer orders an update: a new records review on September 8, 2026, the site visit and interviews on September 10, a new lien search on September 14 and a new declaration on September 15. The 180-day window now runs from September 8 to Sunday, March 7, 2027. The historical research was not redone and still dates from February 2, 2026, so the one-year limit still ends February 2, 2027. Then the closing slips again.

The second row is the trap. The update’s own dates look fine, but they cannot carry the report past one year from the original work. If a closing might move beyond that date, ask the EP to bring the older work current as well, not only the five parts.

SBA loans: one year from the loan number date

U.S. Small Business Administration (SBA) 7(a) and 504 loans follow SOP 50 10 8.1, published September 25, 2026 and effective October 1, 2026. SBA’s September notice applies it to applications received on or after October 1, 2026; an earlier August notice said loan numbers issued on or after that date. SBA posts the SOP only as a Word file.

The core rule is one sentence in Section A, Chapter 5, Paragraph E.3: “Environmental Investigation Reports must be dated within one year of the date of issuance of the SBA loan number.” Appendix 4 repeats it for the Environmental Questionnaire, the Records Search with Risk Assessment (RSRA), the Transaction Screen and the Phase I. Paragraph E.6.a applies the same one-year limit to the lead risk assessment and drinking water tests required for child-occupied facilities built before 1978. The 2025 SOP, as in effect from June 1, 2025, used the same rule.

For the Phase I, Appendix 4 addresses EPA’s clock directly: SBA will accept for review an otherwise AAI-compliant Phase I dated within one year of the loan number date, “notwithstanding the EPA’s regulations on updating Phase I ESAs after 180 days.” The next sentence is a warning: “Parties may still wish to strictly comply with EPA’s regulatory timeframes to avoid jeopardizing legal and regulatory protections.” The acceptance rule does not apply to liquidations under SOP 50 55 or SOP 50 57.

SBA’s test differs from EPA’s in two ways. It is measured to the date the loan number is issued, not to the closing, and it refers to the date of the report, not to the component dates. The SOP does not say whether a report dated after the loan number is acceptable, so ask your lender if yours is.

In an SBA purchase, then, two tests apply. Take one deal with these dates:

• SBA’s test: met. The report is dated 217 days before the loan number was issued, within one year. It would meet SBA’s test for loan numbers issued through April 17, 2027.
• The buyer’s CERCLA test: update needed. The closing is 291 days after April 6, 2026. The 180-day window closed on October 3, 2026, and the one-year limit runs to April 6, 2027. The five parts must be updated before closing for the Phase I to count toward the buyer’s landowner protections.

That gap is what SBA’s warning points to. For most buyers the relevant protection is the bona fide prospective purchaser (BFPP) defense (42 U.S.C. 9601(40)). A current Phase I satisfies one of its requirements; the defense also depends on your own inquiries before closing and on continuing obligations after it, such as required notices, reasonable steps to stop or prevent releases, and cooperation with response actions. Whether you qualify is a question for your attorney.

SBA’s reliance letter allows for updated reports: the Appendix 5 letter, required with every Transaction Screen, Phase I and Phase II, has a box for “A Phase I (or an Updated Phase I).” An update done before closing will usually be dated after the loan number, and the SOP does not say whether that order matters, so confirm with your lender. An RSRA needs no reliance letter, and the form has no RSRA option. The SBA environmental requirements guide explains which report a loan needs.

Other lenders, refinances and leases

The federal clocks govern the buyer’s inquiry, which is one condition of the CERCLA protections, not the only one; they do not bind a lender. A lender’s own protection, the secured creditor exemption, does not depend on AAI, although EPA notes that banks may protect collateral value by requiring borrowers to qualify for the landowner protections (EPA lender liability fact sheet, p. 3).

The handbook that Office of the Comptroller of the Currency (OCC) examiners use for national banks and federal savings associations sets no report-age rule either. It expects a bank’s environmental policies to “reflect adequate consideration of the EPA’s AAI rule” and to set risk thresholds, by property type, use and loan amount, for when and what due diligence is required (Comptroller’s Handbook, Commercial Real Estate Lending, pp. 66-67). Your lender’s credit policy sets the age it accepts, so ask for the limit in writing.

Some articles say most lenders accept a report up to six months old. We found no data behind that claim, and the only published six-month limit in our research is Freddie Mac’s. The published rules, as of October 2026:

A refinance involves no acquisition, so the AAI rule’s clock has no date to run to. E1527-21 measures a lease or refinance to the date of the intended transaction (section 4.6.1), and the lender’s rules decide. For example, if the full underwriting package for a Freddie Mac refinance is delivered on Thursday, November 19, 2026, a report dated April 24, 2026 is almost seven months old that day and would need updating. Freddie Mac’s rule, like SBA’s, is written in terms of the report date, not the component dates.

Your closing slipped: update, new Phase I or reliance letter

Each fix solves a different problem:

What an update involves. It redoes the five time-sensitive parts in the first table: new interviews, a new government records review, a new site visit, a current lien search (yours, unless you hire the EP to run it) and a new EP declaration in an updated report. It also brings the earlier information current for changes at the property and for what you and the EP now know, as 312.20(c)(4) requires.

Our Phase I update includes a new government records search, a new site visit and new interviews, a reissued report with a new declaration by an Environmental Professional who meets 40 CFR 312.10, and the SBA Appendix 5 reliance letter for an updated Phase I. The historical research is kept from the original report, and the cleanup lien search stays with you as the user under E1527-21. We can usually update another firm’s report if it meets E1527-21 and we can review it and perform the update components ourselves. Past one year, order a new Phase I.

Using the seller’s report, or any report prepared for someone else. Section 312.20(d) allows it if the report meets the rule’s objectives and performance factors and you review it, complete your own inquiries into specialized knowledge, purchase price and commonly known information (312.28 to 312.30), and update it as needed. In EPA’s words, it “is not sufficient to wholly adopt” an earlier inquiry “without any review” (70 FR 66084).

Relying on the report is a separate, contractual question. E1527-21 gives no right to rely on a prior assessment (section 4.7.1); a reliance letter from the firm that wrote it does. Fannie Mae multifamily goes further: the borrower may not rely on the Phase I the lender ordered (Form 4251, Section 1.D). The SBA reliance letter guide explains SBA’s fixed form.

When to order so you do not need an update

With 180 days of room, the simplest way to avoid an update is to order once the purchase agreement is signed and the closing date is realistic, not at the letter of intent.

1. Start from a realistic closing date, including lender and SBA processing time. If the date is uncertain, make sure the 180 days reach the latest likely closing date.
2. Order inside your due diligence period. Our standard Phase I takes 5 business days from authorization and confirmed site access; how long a Phase I takes covers each step and what can delay it.
3. Keep your lien search in the same window. Its date is one of the five, so a lien search run months earlier can force an update on its own.
4. Recheck the dates the day the closing moves, not the week before closing. An update needs a new site visit, which has to be scheduled.
5. For an SBA loan, check both tests: the report date against the loan number date, and the component dates against the closing date.

Enter your dates in the Phase I validity calculator. It applies both federal clocks, lets you enter the oldest work separately for an updated report, and has an SBA option that checks the report date against the loan number date.

Sources

1. 40 CFR Part 312, Innocent Landowners, Standards for Conducting All Appropriate Inquiries, eCFR (sections 312.1, 312.10, 312.11 and 312.20 to 312.30; current as of October 16, 2026), accessed October 2026.
2. Standards and Practices for All Appropriate Inquiries, final rule, 70 FR 66070 (November 1, 2005), U.S. Environmental Protection Agency, Federal Register, accessed October 2026.
3. Brownfields All Appropriate Inquiries, U.S. Environmental Protection Agency (last updated May 7, 2026), accessed October 2026.
4. ASTM E1527-21, Standard Practice for Environmental Site Assessments: Phase I Environmental Site Assessment Process, ASTM International (public scope and significance sections), accessed October 2026.
5. Enforcement Discretion Guidance Regarding Statutory Criteria for Those Who May Qualify as CERCLA Bona Fide Prospective Purchasers, Contiguous Property Owners, or Innocent Landowners (“Common Elements”), U.S. Environmental Protection Agency, July 29, 2019, accessed October 2026.
6. SOP 50 10 8.1, Lender and Development Company Loan Programs with Technical Policy Updates, U.S. Small Business Administration (effective October 1, 2026; .docx), accessed October 2026.
7. Information Notice 5000-882227, Issuance of Technical Updates to SOP 50 10 8.1, U.S. Small Business Administration, September 25, 2026, accessed October 2026.
8. Information Notice 5000-880695, Issuance of SOP 50 10 8.1, U.S. Small Business Administration, August 14, 2026, accessed October 2026.
9. 42 U.S.C. 9601, Definitions, U.S. Code, 2024 edition, U.S. Government Publishing Office, accessed October 2026.
10. Lender Liability and Applicability of All Appropriate Inquiries, U.S. Environmental Protection Agency fact sheet EPA-560-F-23-006 (2023), accessed October 2026.
11. Comptroller’s Handbook: Commercial Real Estate Lending, Office of the Comptroller of the Currency (Version 2.0, March 2022, as of March 20, 2025), accessed October 2026.
12. Multifamily Seller/Servicer Guide, Chapter 61: Environmental Requirements, Freddie Mac (Guide Bulletin update of August 25, 2026), accessed October 2026.
13. Form 4251, Environmental Due Diligence Requirements (April 2025), Fannie Mae Multifamily (the same form is in the Fannie Mae Multifamily Guide), accessed October 2026.