Scope: First Aid Kits — pre-assembled, multi-item kits sold as one product for treating injuries (workplace/ANSI-ISEA Z308.1 kits, home/family kits, outdoor & wilderness/trauma kits, vehicle & travel kits). Individual wound-care items sold alone (tape, gauze, bandages) are the medical-tapes leaf; standalone cotton/swabs are cotton-balls; eye-flush devices are eye-washes.

Seed:
1. First-aid equivalent of the treadwear-grade example: the "X-Person" headcount rating printed on every ANSI kit — it's a vendor sizing convention tied to an ANSI/employee-count table, not an absolute injury-coverage count, so it compares loosely across brands (-> rated_group_size, employee_coverage_band).
2. The endurance-athlete persona would notice weight first: an ultralight day kit runs ~4 oz vs ~2-3 lb for a comprehensive backcountry/car kit, and would price supply breadth against ounces carried, not against dollars (-> weight facet, high priority; pieces-per-pound derived metric from the two ANSI spec sheets).

Sources:
[osha_1910_151] https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.151 — requires readily available first aid supplies absent a nearby clinic — fetched via Wayback (osha.gov blocks direct fetch), text confirmed "1910.151(b) ... Adequate first aid supplies shall be readily available."
[osha_1910_151_appA] https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.151AppA — Appendix A labels the ANSI Z308.1 content list "Non-Mandatory" and requires bloodborne-pathogen PPE under 1910.1030(d)(3) — fetched excerpt: "Appendix A to Sec. 1910.151 -- First aid kits (Non-Mandatory) ... described in American National Standard (ANSI) Z308.1-1998".
[wikipedia_first_aid_kit] https://en.wikipedia.org/wiki/First_aid_kit — ANSI/ISEA Z308.1-2021 classifies kits by hazard and container durability; OSHA cites it only in a non-mandatory section; maintenance means checking for expired items — fetched excerpt matched all three claims verbatim.
[redcross_anatomy_of_a_first_aid_kit] https://www.redcross.org/get-help/how-to-prepare-for-emergencies/anatomy-of-a-first-aid-kit.html — family-of-four kit checklist incl. aspirin, antihistamine/hydrocortisone, gloves, thermometer; "Check expiration dates and replace any used or out-of-date contents" — fetched excerpt verbatim.
[firstaidonly_class_a_kit] https://www.firstaidonly.com/10-person-ansi-a-metal-first-aid-kit-ansi-2021-compliant.html — ANSI 2021 Class A, Type III metal case, 76 pieces, 2.35 lb, rated 1-24 employees, contents incl. gloves/CPR shield/trauma pads, no oral medication — fetched via Wayback snapshot, spec table confirmed verbatim.
[firstaidonly_class_b_kit] https://www.firstaidonly.com/100-person-ansi-b-3-shelf-first-aid-cabinet-ansi-2021-compliant.html — ANSI 2021 Class B, Type I&II metal cabinet, 687 pieces, 15 lb, rated 100-149 employees, contents table has refill SKU numbers — fetched via Wayback snapshot, spec table confirmed verbatim.
[stopthebleed_acs] https://www.stopthebleed.org/ — American College of Surgeons program training bystanders in "3 basic actions to control severe bleeding" — fetched homepage text verbatim.
[outdoorlife_best_first_aid_kits] https://www.outdoorlife.com/gear/best-first-aid-kits/ — groups kits by home/car, day-trip, overnight access; weights span 4.1 oz to ~3 lb; flags tourniquet/chest seal/hemostatic gauze/NPA as the backcountry upgrade; waterproof-case kits called out for wet use — fetched article text, all figures matched verbatim.

Branches: workplace_ansi leg supported by osha_1910_151_appA + firstaidonly class A/B pages (ANSI class, PPE, headcount band all vary by this leg). home_family leg supported by redcross_anatomy (checklist/medication differ from workplace). outdoor_wilderness and vehicle_travel legs supported by outdoorlife (weight/trip-tier/bleed-gear/waterproofing are the axes that change).

Noise (spec-sheet rows seen, no facet):
- UPC / part number (firstaidonly) — pure SKU identifier, not expertise.
- Exact case width/height/depth in inches (firstaidonly) — covered qualitatively by case_form_factor; dimensions are packaging detail, not a judgement axis.
- COO / "Assembled in USA" (firstaidonly) — sourcing claim, not a product-performance facet.
- Pet first aid kits (seen in outdoorlife's "Best for Dogs" pick) — out of scope; pet-care products sit outside this human-personal-care leaf.
- "M.A.R.C.H." triage mnemonic and specific trauma-kit brand model names (outdoorlife) — folded into vocabulary/bleeding_control_level rather than separate facets, to avoid padding.

Corrections: fixed derived_metrics field names (why_it_matters->why, added depends_on), renamed reference id osha_1910_151_appA->osha_1910_151_appa (regex), fixed reference `kind` enum values to the schema's allowed set, added osha_1910_151 to certification_label's evidence so every reference is cited.

Corrections (2026-10-26):
- medication_included.why_experts_care rewritten: dropped the false "ANSI kits generally skip medication" claim, now says it varies by class (Class B cabinet ships OTC tablets per firstaidonly_class_b_kit contents table); backfill_note no longer defaults ANSI kits to none by kit type.
- workplace_ansi branch: removed medication_included from makes_irrelevant, added to then_ask (it varies within ANSI kits, confirmed by the Class B contents table).
- home_family branch: removed bloodborne_pathogen_ppe from makes_irrelevant, added to then_ask (Red Cross family-of-four checklist includes gloves).
- weight facet: typical-range text corrected from "15+ lb" to "13.95 lb" cabinet figure; added firstaidonly_class_b_kit to the facet's evidence array; range.max adjusted from 240 to 224 oz to match.
- firstaidonly_class_a_kit and firstaidonly_class_b_kit reference `supports` text corrected to the live spec-table weights: 2.3 lb (was 2.35) and 13.95 lb (was 15).
- derived_metrics.pieces_per_pound `why` text recomputed from corrected weights: 32-46 -> roughly 33-49 pieces/lb (76/2.3, 687/13.95).
- Added facet `case_material` (metal/plastic/fabric_or_unspecified): fetched the plastic variant of the Class A kit directly (firstaidonly.com, 301-redirects to firstaidonly.com/products/10-person-ansi-a-plastic-first-aid-kit-ansi-2021-compliant), confirmed Material: Plastic, 1.35 lb, 76 pieces, $46.51 vs. the metal version's Material: Metal, 2.3 lb, $72.65-range; added as reference `firstaidonly_class_a_plastic_kit`.
- Added facet `splint_included` (included/not_included): firstaidonly_class_b_kit's contents table has its own "Padded Flexible Splint, 4.25in x 24in" line; outdoorlife_best_first_aid_kits separately flags a missing splint as a negative. Both already in the register's reference list.
- employee_coverage_band: source relabeled listing->derived; listing_field_hint now says the band cutoffs aren't printed, only the person-rating is, and the band is mapped from it.
- trip_duration_tier: source relabeled listing->researched, backfill_cost raised low->medium; listing_field_hint/backfill_note now note most retail listings drop the branded product-line name this depends on.
- Added vocabulary entry for "American Red Cross" (facet red_cross_coverage_match), parallel to the existing ANSI/OSHA glosses.
- bleeding_control_level evidence array: added firstaidonly_class_b_kit (its contents table lists a "Windlass Tourniquet", on-point for the includes_tourniquet tier).
- Rejected: check.md Part A's flag that `item_count`/76-piece and 687-piece figures are fine as stated (confirmed verbatim on direct fetch of both firstaidonly pages, no change needed) — not a required fix, just re-verified during this pass.
- Verified via direct fetch (not Wayback) of both firstaidonly.com spec pages: 76 pieces/2.3 lb (Class A), 687 pieces/13.95 lb (Class B), "Padded Flexible Splint" and "Antacid Tablets"/"Extra Strength Non-Aspirin Tablets" lines all present verbatim, confirming check.md's findings.