Use required weather and release assumptions in offsite consequence analysis

Frame this document as a source-led configuration and assurance check: Use required weather and release assumptions in offsite consequence analysis. Only the official source and traced locations below supply facts. Confirm applicability before acting.

Source fact:

The official 40 CFR 68.22 — Chemical Accident Prevention Provisions from Environmental Protection Agency via eCFR supports the following bounded statements:

• Under 40 CFR 68, the rule requires that the worst-case release of a regulated toxic substance be analyzed assuming a ground level (0 feet) release. The research record locates this support at 40 CFR 68.22(d) (eCFR anchor p-68.22(d)).
• Under 40 CFR 68, the rule requires that for the worst-case release analysis, the owner or operator use a wind speed of 1.5 meters per second and F atmospheric stability class. The research record locates this support at 40 CFR 68.22(b) (eCFR anchor p-68.22(b)).

The source support ends with the statements listed above. Use them to examine critical rooms, power, cooling, water, fire protection, alternate sites, physical barriers, and documented recovery paths in the applicable environment, not to imply a wider guarantee.

What the source does not establish

Applies only to stationary sources and processes subject to 40 CFR part 68 and the applicable program level. Confirm coverage, regulated substances, process conditions, and current EPA requirements; this is not legal advice or a universal emergency-management standard. Do not read the source as proof of implementation or permission to change production. Its guidance remains conditional on identity and access control, Windows DNS where networked services use it, time, communications, utilities, life-safety systems, vendors, and authorized responders and the environment’s recorded constraints.

Applicability questions

• For source statement 1 at 40 CFR 68.22(d) (eCFR anchor p-68.22(d)), which observable configuration, record, or test can confirm applicability here?
• For source statement 2 at 40 CFR 68.22(b) (eCFR anchor p-68.22(b)), which observable configuration, record, or test can confirm applicability here?
• Which owner can attest to the recorded state of critical rooms, power, cooling, water, fire protection, alternate sites, physical barriers, and documented recovery paths, including exceptions?
• What baseline for identity and access control, Windows DNS where networked services use it, time, communications, utilities, life-safety systems, vendors, and authorized responders must accompany the source-specific observation?
• Which success, stop, and escalation criteria are written before testing begins?

DSE recommendation:

DSE recommends using the cited source as the evidence anchor for this decision. Make the source, asset scope, owner, and expected outcome explicit in the review record. Record the source location, examined part of critical rooms, power, cooling, water, fire protection, alternate sites, physical barriers, and documented recovery paths, observed and expected states, owner, and reason for deviation.

For an approved change, define prerequisites, a limited test path, success and stop conditions, monitoring, and rollback. Check identity and access control, Windows DNS where networked services use it, time, communications, utilities, life-safety systems, vendors, and authorized responders in design order. Protect credentials, keys, recovery material, personal data, and sensitive topology in evidence.

Verification and evidence

Build a reproducible chain from 40 CFR 68.22(d) (eCFR anchor p-68.22(d)); 40 CFR 68.22(b) (eCFR anchor p-68.22(b)) to the observed environment. Useful domain evidence includes facility inventories, inspection records, alarm and shutdown tests, maintenance history, recovery exercises, and corrective actions; label every item with scope, timestamp, collector, and stable identifier.

Retain the starting state, authorization, execution record, outcome, deviation, and final state as one review package. Move disruptive checks to an approved test path. Reopen the decision when versions, design, dependencies, ownership, or official guidance changes.

Official references

• 40 CFR 68.22 — Chemical Accident Prevention Provisions — Environmental Protection Agency via eCFR