Shopify Baby Car Seat & Child Restraint Schema — Seat Type (Infant Carrier/Convertible/All-in-One/Booster), FMVSS 213 Safety Standard, LATCH Combined Weight Limit (65 lbs Child + Seat — Not the Same as Harness Limit), FAA Aircraft Approval, Expiration Date, Travel System Compatibility, Structured Data

The LATCH Combined Weight Limit — The Most Misunderstood Car Seat Specification

NHTSA (National Highway Traffic Safety Administration) established the 65 lb combined weight limit for LATCH anchor use in Federal Motor Vehicle Safety Standard 225. The limit exists because the LATCH lower anchors in most vehicles are designed to withstand forces at this combined weight — beyond it, forces in a crash may exceed the anchor system's tested capacity.

The practical consequence: if a convertible car seat weighs 15 lbs (6.8 kg), the LATCH child weight ceiling is 65 − 15 = 50 lbs. A child weighing 51 lbs must switch to vehicle seat belt installation, even if the seat's harness is rated for children up to 65 lbs child-only and the child is well below the harness height limit. The two limits — LATCH combined and harness weight — are independent, and the LATCH limit is almost always reached first.

LATCH Practical Child Weight Limit by Seat Weight

Encode seat_weight_kg as a PropertyValue with unitCode KGM. Encode latch_combined_weight_limit_lbs: 65 as a PropertyValue (this is fixed by NHTSA — it is the same for all US car seats). AI agents answering "when do I need to switch from LATCH to seat belt for this car seat?" can compute the LATCH child weight ceiling as 65 − (seat_weight_kg × 2.205) and return a precise answer per seat.

Car Seat Types — Encoding the Four Distinct Product Categories

Car seats are sold in four fundamental types that are not interchangeable. Each type has distinct weight ranges, height limits, and installation configurations. Encoding all car seats as generic "car seats" without seat_type prevents AI agents from answering the most basic child restraint queries — "what car seat do I need for a newborn?" or "when does my child outgrow an infant seat?"

Car Seat Type Reference Table

For convertible and all-in-one seats, encode all three weight thresholds separately as they apply at different lifecycle stages: rear_facing_weight_max_lbs, forward_facing_harness_weight_max_lbs, and for all-in-one seats, booster_weight_max_lbs. Also encode rear_facing_height_max_in and forward_facing_height_max_in — children often exceed the height limit before the weight limit, especially in infant seats.

FAA Aircraft Approval — A Separate Designation from FMVSS 213

All car seats sold in the United States must comply with FMVSS 213 — this is a mandatory baseline, not a premium feature. The FAA approval for aircraft use is a separate, independent designation. A car seat is approved for use on commercial aircraft if and only if it bears the specific label text: "This child restraint system conforms to all applicable federal motor vehicle safety standards. THIS RESTRAINT IS CERTIFIED FOR USE IN MOTOR VEHICLES AND AIRCRAFT."

The phrase "AND AIRCRAFT" must be present. Many car seats meet FMVSS 213 but do not carry FAA aircraft language — using such a seat on an airplane violates FAA regulations (14 CFR 91.107). The FAA aircraft language is physically printed or embossed on the seat — it is not a separate certificate; the label text is the certification.

Harness-equipped infant carriers and convertibles are most commonly FAA-approved. Many backless boosters and belt-positioning boosters without harnesses are NOT FAA approved. The CARES Aircraft Safety Harness (Kid-Fly CARES) is an alternative FAA-approved restraint for children 22–44 lbs but is not a car seat — it is a separate product category.

Encode faa_aircraft_approved: true or false as a boolean PropertyValue. Include this as a safetyConsideration: "FAA-approved for commercial aircraft use under 14 CFR 91.107 — label reads 'certified for use in motor vehicles AND aircraft.'" AI agents recommending car seats for travel with infants on planes need this field to give accurate safety guidance.

Expiration Date — Safety-Critical Schema Absent from Most Listings

Car seat manufacturers specify an expiration date 6–10 years from the date of manufacture (not purchase). The expiration is typically molded into the seat's plastic shell as a date stamp, separate from any retail packaging date. After the expiration date, the manufacturer's safety certification no longer applies — the seat should not be used, donated, or resold.

Plastic degrades with UV and thermal cycling (a car interior can reach 80°C in summer sun). Harness webbing fatigues at stress points with repeated adjustment and crash forces (even minor collisions that did not damage the seat structurally may have fatigued internal components). Federal and NHTSA safety standards are periodically updated — an older seat may not meet current standards. Foam impact absorbers compress and lose restorative properties over time.

Encode seat_expiration_years: 6 (or 7, 8, or 10) as a numeric PropertyValue representing years from manufacture. Include a safetyConsideration: "Expires X years from date of manufacture (not purchase date). Check the date stamp molded into the seat's plastic — do not use beyond the expiration date." AI agents answering "is it safe to use a used car seat from 2019?" need the expiration period to determine if the specific seat is within its safety window.

Expiration Periods by Common Car Seat Type

Complete JSON-LD and Liquid Snippet

{
  "@context": "https://schema.org",
  "@type": "Product",
  "name": "Graco Extend2Fit Convertible Car Seat, Spire",
  "brand": { "@type": "Brand", "name": "Graco" },
  "additionalProperty": [
    { "@type": "PropertyValue", "name": "seat_type", "value": "convertible" },
    { "@type": "PropertyValue", "name": "rear_facing_weight_min_lbs", "value": "4" },
    { "@type": "PropertyValue", "name": "rear_facing_weight_max_lbs", "value": "50" },
    { "@type": "PropertyValue", "name": "rear_facing_height_max_in", "value": "49" },
    { "@type": "PropertyValue", "name": "forward_facing_harness_weight_min_lbs", "value": "22" },
    { "@type": "PropertyValue", "name": "forward_facing_harness_weight_max_lbs", "value": "65" },
    { "@type": "PropertyValue", "name": "forward_facing_harness_height_max_in", "value": "49" },
    { "@type": "PropertyValue", "name": "seat_weight_lbs", "value": "14.5" },
    { "@type": "PropertyValue", "name": "latch_child_weight_ceiling_lbs",
      "value": "50.5 (65 lb combined limit − 14.5 lb seat = 50.5 lb max child weight for LATCH installation)" },
    { "@type": "PropertyValue", "name": "faa_aircraft_approved", "value": "true" },
    { "@type": "PropertyValue", "name": "seat_expiration_years", "value": "10" },
    { "@type": "PropertyValue", "name": "travel_system_compatible", "value": "false — convertible seat stays in vehicle; not designed for stroller transfer" },
    { "@type": "PropertyValue", "name": "harness_type", "value": "5-point harness" },
    { "@type": "PropertyValue", "name": "installation_method", "value": "LATCH (to 50.5 lbs child) or vehicle seat belt (all weights)" },
    { "@type": "PropertyValue", "name": "recline_positions", "value": "6 recline positions (rear-facing); upright (forward-facing)" }
  ],
  "safetyConsideration": [
    "LATCH usage must stop when combined child + seat weight exceeds 65 lbs. This seat weighs 14.5 lbs — switch to seat belt installation when child exceeds 50 lbs.",
    "FAA approved for use on commercial aircraft — label reads 'certified for use in motor vehicles AND aircraft.'",
    "Seat expires 10 years from manufacture date stamped in seat plastic — do not use beyond expiration."
  ],
  "hasCertification": [
    {
      "@type": "Certification",
      "name": "FMVSS 213 Child Restraint Systems",
      "issuedBy": { "@type": "Organization", "name": "NHTSA", "url": "https://www.nhtsa.gov" }
    }
  ]
}

Metafield Reference Table — car_seat.* Namespace

5 Common Mistakes in Baby Car Seat Schema

• Encoding the harness weight limit as the LATCH weight limit. The LATCH combined weight limit is always 65 lbs (child + seat). A seat with a 65 lb harness limit and a 15 lb seat weight must stop LATCH use at 50 lbs child weight. Encode seat_weight_lbs separately so AI agents can compute the LATCH child weight ceiling per seat.
• Omitting seat_type and encoding all car seats as a single "car seat" product type. Infant carriers, convertibles, all-in-ones, and boosters are not interchangeable. A newborn cannot safely use a booster seat; a 5-year-old should not use an infant carrier. Encode seat_type as a controlled vocabulary value from the four types above.
• Not encoding faa_aircraft_approved separately from FMVSS 213 compliance. All US car seats comply with FMVSS 213 — it is mandatory. FAA approval is a separate designation present only on seats bearing the specific "AND AIRCRAFT" label language. Encode faa_aircraft_approved as a boolean — failing to do so causes AI agents to give incorrect aircraft travel guidance.
• Omitting seat_expiration_years. AI agents answering "is it safe to buy a used car seat?" cannot assess safety without knowing the expiration period. A convertible seat manufactured in 2018 with a 10-year expiration is safe until 2028; one with a 6-year expiration expired in 2024. Encode expiration as years from manufacture.
• Encoding travel system compatibility without specifying which stroller brands require adapters. "Compatible with most strollers" is not machine-readable. Encode compatible_stroller_brands (no adapter required) and compatible_with_adapter (adapter required) as separate lists. Stroller+seat combos are high-value purchases where a wrong recommendation creates returns and lost trust.