Cairn No. 01

Source Notes

The agencies and guidance this cairn was checked against, with URLs and access dates.

This cairn is not original research. It is a careful synthesis of standing guidance from federal agencies, fire-safety organizations, and academic extension services, written in plain language for a household audience. The specific factual claims — refrigerator and freezer safety windows, carbon monoxide rules, the twenty-foot operating distance for fuel-burning equipment, the never-taste-food rule, household-communication guidance during outages — were checked against the sources below.

If you are a clinician, emergency manager, or domain expert who finds an error here, please tell us. The work is freely usable; the verification is ongoing.

Verification lane

Yellow. Claims verified against the federal agency, fire-safety organization, and academic-extension sources listed below. No expert review on this cairn.

Sources used

U.S. Food and Drug Administration (FDA) — Food and Water Safety During Power Outages and Floods. fda.gov. Accessed 2026-05-12. Used for: closed-refrigerator food-safety duration (about 4 hours); full-freezer duration (about 48 hours); half-full freezer duration (about 24 hours); when to discard perishable refrigerated food held above 40°F.

U.S. Department of Agriculture, Food Safety and Inspection Service (USDA FSIS) — Keeping Food Safe During an Emergency. fsis.usda.gov. Accessed 2026-05-12. Used for: independent confirmation of FDA food-safety figures; the explicit never taste food to determine its safety rule; perishable categories.

foodsafety.gov — Food Safety in a Disaster or Emergency. foodsafety.gov. Accessed 2026-05-12. Used for: federal aggregated food-safety guidance; independent confirmation of refrigerator and freezer windows.

Oregon State University Extension — Is my food still safe after power outages? extension.oregonstate.edu. Accessed 2026-05-12. Used for: independent academic-extension confirmation of the 4-hour refrigerator rule and the 40°F / 2-hour rule for refrigerated food after temperature rise; signs of spoilage.

U.S. Centers for Disease Control and Prevention (CDC) — What to Do to Protect Yourself During a Power Outage. cdc.gov. Accessed 2026-05-12. Used for: carbon monoxide guidance during outages; generators and gasoline-powered engines outdoors only and at least 20 feet from doors, windows, and vents; heat- and cold-related medical risk; medically vulnerable household considerations.

U.S. Centers for Disease Control and Prevention (CDC) — Carbon Monoxide Poisoning Basics. cdc.gov. Accessed 2026-05-12. Used for: CO is colorless, odorless, and can kill without warning; common household sources of CO including portable generators and charcoal grills.

National Fire Protection Association (NFPA) — Candles (home fire safety). nfpa.org. Accessed 2026-05-12. Used for: candles as a cause of home fires and home fire deaths; the recommendation against using candles for emergency lighting.

National Fire Protection Association (NFPA) — Generator Safety Tip Sheet. nfpa.org. Accessed 2026-05-12. Used for: portable generators must be operated outdoors in well-ventilated areas; the at-least-twenty-feet operating distance from doors, windows, and vents.

Federal Emergency Management Agency (FEMA) — Frequently Asked Questions About Disasters. fema.gov. Accessed 2026-05-12. Used for: text messages may get through when voice calls cannot during disaster-related cellular network congestion.

Ready.gov — Power Outages. ready.gov. Accessed 2026-05-12. Used for: overall household guidance for power outages; phone-battery conservation; alternative power sources; household communication.

Ready.gov — Build a Kit. ready.gov. Accessed 2026-05-12. Used for: emergency kit basics including cell phone, chargers, and a backup battery as named disaster-supply items.

Ready.gov — Get Tech Ready. ready.gov. Accessed 2026-05-12. Used for: text messages, social media, and email as preferred emergency-communication tools; phone-battery conservation including low-power and airplane modes.

Expert review status

No expert review on this cairn. The Yellow-lane verification standard was met through the federal agency, fire-safety, and academic-extension sources listed above.

A note on changing guidance

Federal and state agencies update their guidance from time to time. The four-hour and forty-eight-hour windows have been stable for many years, as have the rules on fuel-burning equipment indoors. If you find that a specific number or rule above has been updated by the issuing agency, the agency's current guidance should be considered authoritative over what is written here, and we would be grateful to hear about it.

Corrections

If you find a factual error in this cairn, please tell us through the contact page. Corrections are recorded openly.

Version history

v1.0 — 2026-05-12 — Initial publication.