What a Phase I does not cover

A Phase I under ASTM E1527-21 looks for the hazardous substances within CERCLA's scope and for petroleum products, and the standard confines its use strictly to that scope (E1527-21, 1.1, 1.4). What a party may want assessed beyond it are non-scope considerations. No assessment of them is required for all appropriate inquiries, and a user who wants one added should agree it with the environmental professional as an additional service before the assessment starts (E1527-21, 1.4, 13.1.1, 13.1.2).

The standard's list

The standard names sixteen non-scope considerations, says the list is not all-inclusive, and says it implies nothing about their relative importance (E1527-21, 13.1.5). Grouped here for reading, they are:

Building materials. Asbestos-containing building materials and lead-based paint, each where no release into the environment is involved; PCB-containing building materials, such as interior fluorescent light ballasts, paint and caulk.
Indoor conditions and water. Indoor air quality, where no hazardous substance or petroleum product has been released into the environment; mold or microbial growth conditions; naturally occurring radon; lead in drinking water.
Natural and cultural resources. Wetlands; endangered species; ecological resources; cultural and historic resources.
Workplace and compliance. Health and safety; industrial hygiene; regulatory compliance.
Other. Biological agents; substances that are not CERCLA hazardous substances, some emerging contaminants among them, until they are classified as hazardous substances.

Other limits the standard sets

No sampling. The practice includes no testing or sampling of soil, water, air or building materials (E1527-21, 7.4).
Controlled substances are outside it, except as the terms of an EPA brownfields assessment grant bring them in (E1527-21, 1.1).
Other legal duties. It does not address CERCLA duties beyond all appropriate inquiries, such as the continuing obligations, or other federal, state or local laws (E1527-21, 1.1.3, 1.1.4). Whether a party complies with activity and use limitations is beyond its scope (E1527-21, 13.1.4).
The site, not the business. It is site-specific and leaves out many issues of buying a business or its assets, such as liabilities for properties once owned or operated (E1527-21, 4.2.3).
What the site visit need not do. It need not find hidden conditions, such as what lies behind walls, below floors or above ceilings, or what is on rooftops, or listed features that cannot be seen or reached during the visit (E1527-21, 9.2.4).
Not exhaustive. All appropriate inquiries is not an exhaustive assessment, and no assessment wholly removes uncertainty (E1527-21, 4.5.1, 4.5.2).

How a user adds one

Whether to include a non-scope item should be weighed against the nature of the property and the reason for the assessment (E1527-21, 1.4). Additional services may take in business environmental risk: the risk that environmental matters will materially affect the business tied to the property's current or planned use, whether or not the practice covers that risk (E1527-21, 3.2.11, 4.4). Such services are beyond the practice and should appear in the report only if the terms of engagement call for them (E1527-21, 12.10), and the report lists every addition to the practice (E1527-21, 12.11). Other standards or protocols may exist for assessing non-scope conditions (E1527-21, 13.1.3).

The suggested report format, in a nonmandatory appendix, has a Non-Scope Services section, included as the user and the environmental professional agree, and lets business environmental risks tied to those services be discussed with the findings and conclusions (E1527-21, X5.7 to X5.9).

The nonmandatory appendix on common non-scope issues

The appendix says evaluating non-scope items is not required for compliance with the AAI rule or the practice, and has no bearing on it. Putting one in a Phase I report is entirely the user's call, based on its risk tolerance and the needs of the transaction, and the appendix is not to be read as requiring any (E1527-21, Appendix X6 introduction). It discusses several listed items in more detail, among them asbestos-containing building materials, radon, lead-based paint, mold, wetlands and substances not defined as hazardous substances (E1527-21, X6.1 to X6.10). On the last, it says such a substance may be discussed like any other non-scope item where the Phase I also serves state requirements or the user asks, and is to be evaluated within the practice once CERCLA counts it as hazardous (E1527-21, X6.10).

When a non-scope item is still a REC question

The entries for asbestos, indoor air quality and lead-based paint are non-scope only where no release into the environment is involved (E1527-21, 13.1.5.1, 13.1.5.7, 13.1.5.9). The standard and its nonmandatory legal appendix show where that line can be crossed:

PCBs. Electrical or hydraulic equipment known or likely to contain PCBs is a site visit item; ballasts, caulk, paint and similar materials inside and part of the building are outside the practice. A note adds that such materials may need to be identified when they are not part of the building and not confined to its inside (E1527-21, 9.4.18).
Building materials. The legal appendix explains CERCLA's building materials exclusion: it reaches a release from a product built into a structure only when the exposure is also inside that structure, and it can apply to asbestos, lead-based paint and PCB materials. The limit on federal response does not apply if EPA finds that a release or threatened release is an emergency for public health or the environment and nobody else with the authority and means will respond in time (E1527-21, X1.1.4.3).
After demolition. The appendix on non-scope issues notes that a non-scope item in an older Phase I can be a recognized environmental condition in a later one: asbestos-containing materials built into a standing building, with exposure only inside it, fall within that exclusion, but the same materials buried in soil once the building is demolished may no longer do so (E1527-21, Appendix X6 introduction).
Radon. Radon from naturally occurring material entering a building would not normally be a CERCLA release, but radon from radioactive waste that was disposed of or spilled can be (E1527-21, X1.1.4.3).
Vapor. Hazardous substances such as vapors that move into a building from a release outside it can give rise to CERCLA liability (E1527-21, X1.1.1.2).

Whether any of these is a recognized environmental condition at a given property is for the environmental professional to judge on the lines of evidence (E1527-21, 7.3.1, 12.6).

This page is general reference. It does not assess any property. ASTM E1527-21 is the standard and is not reproduced here.