Labels and ratings: what each one measures and what it does not predict

Janka, AC classes, wear layers, porcelain certification, PEI, DCOF, double rubs, cleaning codes, flammability labels, formaldehyde labels, emission certifications, KCMA and Safer Choice: the test behind each, and what it leaves out.

At a glance

Each rating or label below says what it measures, how it is tested, and what it does not predict. A rating compares products under one test; it does not promise how a surface will wear in your home. Samples, ratings, labels and warranties explains how to use them together.

Janka hardness

What it measures. How hard it is to dent a wood species. NWFA calls it a good indication of dent resistance. It is a property of the wood, not of the floor's finish.

The test. A steel ball 0.444 in. across is pushed halfway into the wood; the force it takes, in pounds-force, is the number (NWFA). The USDA Wood Handbook lists side hardness at 12 percent moisture content for clear, defect-free samples: for example northern red oak 1,290, white oak 1,360, sugar maple 1,450, black walnut 1,010, black cherry 950 and shagbark hickory 1,880.

What it does not predict. Scratches: the finish takes those, and its sheen changes how much they show (NWFA). NWFA says none of the Janka values apply to engineered wood flooring. The cut and the finish also affect durability (NWFA). Physical principle

Sources: NWFA durability, USDA Wood Handbook, NWFA finishes.

Laminate wear cycles and AC classes

What it measures. How long the laminate's top wear layer resists abrasion before it first wears through, in a lab.

The test. ANSI/NALFA LF 01-2026, the North American laminate standard, sets four usage levels (Residential, Light Commercial, General Commercial, Heavy Commercial) and a minimum wear result for each, from a Taber-type abrasion test counted in cycles to the first wear point. The 2026 edition also prints AC classes beside the cycle counts. AC classes (AC1 to AC6) come from the European standard EN 13329; in 2022 NALFA's standard did not use them, though laminate marketing did (NALFA white paper). Read the class or level on the box or spec sheet; we do not restate which level gets which number here. LF 01 also covers thickness swell after soaking, static load, castor chairs and formaldehyde compliance of the core.

What it does not predict. NALFA says abrasion class is only one part of durability; impact and stain resistance matter too. Water on an assembled joint and scratching have their own tests (Surface Swell and Macro-Scratch), which NALFA lists as optional, not required by LF 01. A wear class says nothing about water at the edges.

Sources: ANSI/NALFA LF 01-2026, NALFA AC white paper, NALFA certification.

Wear layer

What it measures. On vinyl plank and tile: the thickness of the clear top layer over the printed film, in mils (thousandths of an inch) or millimeters. On engineered wood: the thickness of real wood above the tongue, which decides whether it can be sanded.

The test. Vinyl: ASTM F1700 classifies luxury vinyl tile, and the wear layer is measured by ASTM F410. One commercial spec sheet lists a 0.020 in. (20 mil) wear layer and states F1700's commercial minimum as 0.020 in. (Armstrong). We found no free copy of F1700 and no non-maker source for residential minimums. Engineered wood: wear layers range from 1/16 in. to 1/4 in., and NWFA's magazine advises against sanding one under 3/32 in.; NWFA runs a program that identifies engineered floors that can be sanded.

What it does not predict. Vinyl: dents and scratches have separate tests (indentation under ASTM F1914 and static load under ASTM F970, on the same sheet). One rigid-core warranty counts only full wear-through over at least 3 percent of the floor, and says scratches and gloss loss are not wear (Shaw SmartCore, 2021). Wood: the number of sandings also depends on the contractor, the equipment and how flat the floor is (NWFA).

Sources: Armstrong LVT spec sheet, Shaw SmartCore warranty (2021), Hardwood Floors, sandings, NWFA refinishing.

Porcelain certification

What it measures. Whether a tile absorbs 0.5 percent of its weight in water or less. That is what porcelain means; above 0.5 percent, a tile is non-porcelain (TCNA).

The test. Water absorption by ASTM C373. The Porcelain Tile Certification Agency (PTCA) certifies tiles that meet it, and its mark appears on packaging; TCNA says IPA Laboratories is the only PTCA-authorized lab in the US.

What it does not predict. Frost resistance usually follows low absorption, but not always (TCNA). It says nothing about slip resistance (see DCOF) or glaze wear (see PEI). TCNA reports many cases of non-porcelain tile advertised as porcelain, which is why the mark exists.

Sources: TCNA porcelain, TCNA porcelain certification.

PEI class (glazed tile wear)

What it measures. How well a glazed tile's surface resists visible abrasion.

The test. ASTM C1027 rotates an abrasive load on the glaze and compares the worn and unworn areas by eye. The classes 0 to 5 printed on boxes rest on this test; we found the class descriptions only on retailer pages, not from a standards body or a US maker, so we do not reproduce them. Ask the maker what its class means for floors.

What it does not predict. ASTM's scope says the method makes no allowance for the difference between light and dark tile, may not evaluate irregular surfaces properly, and does not measure loss of gloss well. It applies to glazed tile: through-body porcelain is not rated this way.

Sources: ASTM C1027, TCNA porcelain.

DCOF (dynamic coefficient of friction)

What it measures. Friction between a test slider and the tile surface, wet, as measured by one device.

The test. ANSI A326.3 uses the BOT 3000E device. For level interior spaces that are walked on when wet, which can include home bathrooms and kitchens kept clean and free of standing water, the standard's value is a wet DCOF of 0.42 or more; public showers, pool decks and similar areas use a maker-declared value. The 0.42 figure applies to that device only.

What it does not predict. The standard says DCOF does not predict whether a person will slip, and Daltile repeats it. Shoes, contaminants, stride, the person, slope and upkeep all matter (A326.3). DCOF on an installed floor can change with wear, and a higher-friction surface can be harder to keep clean. For falls in the home, see Tile and grout. Physical principle

Sources: ANSI A326.3, TCNA on DCOF, Daltile DCOF.

Double rubs and Martindale cycles

What it measures. How many rubs a fabric takes in a lab before two yarns break or it shows clear wear.

The test. Wyzenbeek (ASTM D4157) rubs the taut fabric back and forth with cotton duck, or a wire screen for olefin, and counts double rubs. Martindale (ASTM D4966) rubs it in a looping path against wool and counts cycles. ACT's contract guidelines (February 2025) set 15,000 double rubs or 20,000 Martindale cycles for low-traffic private spaces and 30,000 or 40,000 for public spaces. Retailers' residential bands differ from each other and are not a standard (Sailrite).

What it does not predict. Wear life. ASTM D4157 says lab results should not be relied on to predict actual wear life. ACT says twice the rubs does not mean twice the life, repeat tests on one fabric can vary by 60 percent or more, the two tests do not convert, and field failures come mostly from wrong cleaning, poor upkeep and abuse. Both tests measure flat abrasion, not the edges of seats and arms (ACT). ASTM calls Martindale's between-lab precision poor. Convention

Sources: ASTM D4157, ASTM D4966, ACT guidelines (2025), ACT abrasion disclaimer, ACT abrasion white paper (2010), Sailrite wear ratings.

Cleaning codes W, S, W/S and X

What it measures. Which kind of cleaner the furniture or fabric maker allows.

The test. We found no test and no federal standard behind them. The codes are each maker's convention: the FTC's care label rule covers clothing and fabric sold for home-sewn clothing, not upholstered furniture. The common reading (Sailrite, American Leather): W water-based cleaner, not machine washable; S water-free solvent only, since water can leave rings; W/S either; X vacuum or brush only. Some makers use other codes, such as DC, HW and MW (Ashley). The tag is usually under a cushion or on the base.

What it does not predict. How the fabric will clean in practice. For X, Sailrite says vacuum or brush; American Leather says hire a professional. A stain repellent does not change which cleaners a fabric tolerates (ACT). Pre-test on a hidden spot whatever the code (Sailrite). Product-specific

Sources: Sailrite cleaning codes, American Leather cleaning codes, Ashley cleaning codes, 16 CFR 423, ACT on stain repellents.

TB 117-2013 and the federal flammability label

What it measures. Whether upholstery materials keep smoldering, or burst into flame, when a lit cigarette rests on them.

The test. California's Technical Bulletin 117-2013 tests cover fabric, barrier and filling in mock-ups for 45 minutes and limits char length. Since June 25, 2021, 16 CFR 1640 makes it the federal standard for upholstered seating, with a permanent label from June 25, 2022 reading "Complies with U.S. CPSC requirements for upholstered furniture flammability." Mattresses are under other rules.

What it does not predict. Open flame: the bulletin says its methods are not meant to measure open-flame exposure. The standard tests how the materials behave, not which chemicals they contain, so the label does not tell you whether flame retardants were used.

Sources: TB 117-2013, 16 CFR 1640, CPSC upholstered furniture FAQ.

California's flame retardant statement

What it measures. Whether the cover fabric, barrier, filling or decking of a piece sold in California contains added flame retardant chemicals.

The test. No test: a label required since January 1, 2015, on upholstered furniture sold in California that must meet TB 117-2013. It prints two lines, "contain added flame retardant chemicals" and "contain NO added flame retardant chemicals", with an X by the one that applies.

What it does not predict. Which chemicals, how much, or anything about health. California's bureau says it has no authority outside California and knew of no other state with the statement, so furniture sold elsewhere may not carry it. Outdoor furniture and mattresses are not required to. Ask the authority

Sources: California SB 1019 FAQ.

TSCA Title VI (formaldehyde in composite wood)

What it measures. Formaldehyde released from hardwood plywood, MDF and particleboard, and from finished goods made with them: cabinets, furniture, and the fiberboard core of laminate flooring.

The test. Federal limits since June 1, 2018, by a chamber test: hardwood plywood 0.05 ppm, particleboard 0.09 ppm, MDF 0.11 ppm, thin MDF 0.13 ppm. Since March 22, 2019, these products must be labeled TSCA Title VI compliant. A finished good that is not labeled itself must have its label kept by the retailer, who must show it to a customer on request. Optional claims, NAF (no added formaldehyde-based resins) and ULEF (ultra low-emitting), need separate certification. An EPA rule of October 2026 updates the test standards the rule refers to; EPA says the limits do not change.

What it does not predict. Solid wood, and finishes or adhesives applied at home, are not covered. Vinyl and carpet are not composite wood. The label is a compliance mark, not a statement about health; EPA's own pages on formaldehyde exposure are the place for that. Ask the authority

Sources: EPA composite wood rule, 40 CFR 770, ANSI/NALFA LF 01-2026.

FloorScore

What it measures. Emissions of listed volatile organic compounds (VOCs) from hard-surface flooring and its adhesives.

The test. Certified by SCS Global Services against California's Section 01350 method (CDPH Standard Method v1.2): samples are conditioned, tested in a chamber, and judged on the emission at 14 days, modeled into a standard classroom and office. FloorScore adds plant audits and yearly re-testing (RFCI).

What it does not predict. RFCI says it does not include the installation. It does not address phthalates, PFAS, recycled content, durability or slip resistance. The CDPH method does not model a home, and does not test odor, flame retardants or emissions after the product ages in place. Convention

Sources: RFCI FloorScore, CDPH Standard Method v1.2.

Green Label Plus

What it measures. Emissions of listed VOCs from carpet, cushion and carpet adhesive.

The test. UL Solutions tests samples in a small chamber (ASTM D5116) against CRI's criteria, Issue 5 of August 20, 2026: California Section 01350 compounds plus carpet-specific ones, such as 4-phenylcyclohexene, the compound behind new-carpet smell. A black-and-white label means the same as the green one (CRI).

What it does not predict. It does not test stain treatments (PFAS), flame retardants or emissions from cleaning. It is a voluntary industry program, not a health rating.

Sources: CRI Green Label Plus, Green Label Plus criteria, Issue 5, CRI FAQ.

GREENGUARD and GREENGUARD Gold

What it measures. Emissions of VOCs from products, under UL 2818.

The test. UL reviews the making of the product and tests it routinely. Gold sets lower limits, covers more than 360 VOCs and total emissions, and must also meet the California method. One Gold certificate lists, for example, total VOCs 0.22 mg/m³ and formaldehyde 9 µg/m³, modeled for an office and a classroom. Certificates expire; UL's SPOT database confirms one.

What it does not predict. Like FloorScore, it models an office or classroom, not a home, and does not test flame retardants or PFAS. We did not find the standard (non-Gold) limits on a page UL makes public.

Sources: UL GREENGUARD, a GREENGUARD Gold certificate, CDPH Standard Method v1.2.

CRI Seal of Approval

What it measures. Whether a carpet cleaning product or machine removes soil without harming the carpet's appearance or performance.

The test. Lab testing of vacuums, extractors, deep-cleaning systems and cleaning solutions under CRI's program manual. Cleaning firms gain the seal by using certified products.

What it does not predict. Anything about the carpet itself: the seal is on cleaners and equipment. CRI says some carpet makers require Seal of Approval cleaners for their warranty, so check yours. Product-specific

Sources: CRI Seal of Approval, CRI cleaning.

KCMA certification (cabinets)

What it measures. Whether a cabinet line passes the ANSI/KCMA A161.1 tests of structure, doors, drawers and finish.

The test. KCMA lists 14 tests. Examples: shelves loaded for seven days; drawers and doors opened 25,000 times under load; the finish exposed to vinegar, grape juice, coffee, alcohol and mustard, and to a humid 120-degree hotbox for 24 hours. KCMA says 40 to 50 percent of cabinets fail their first attempt, and certified cabinets exist at every price point. A separate Severe Use certification, first developed by HUD for high-turnover apartments, is its own tier. The ESP program certifies makers, not cabinets.

What it does not predict. The standard itself is sold, so exposure times and the full substance list are not public. It does not cover installation, and it does not say how a finish will look after years of your own cleaning. KCMA mediates warranty disputes for certified cabinets.

Sources: KCMA one-sheet, KCMA certification, KCMA, certified cabinetry, KCMA Severe Use.

Safer Choice

What it measures. EPA's review of every chemical ingredient in a cleaning product, whatever its percentage.

The test. A voluntary EPA program. Criteria cover cancer, reproductive and aquatic toxicity, persistence, pH limits to reduce skin and eye irritation, and VOC content; products must perform comparably to conventional ones, and EPA audits them yearly. Disinfectants are listed separately, as Design for the Environment (DfE) certified.

What it does not predict. Whether the product suits your surface: stone, wood finish or quartz compatibility is still the surface maker's call. Read the floor or counter maker's sheet as well as the cleaner's label. Ask the authority

Sources: EPA Safer Choice label.