Reference Matrix 02 · International Textile Care Labelling Standards (ISO 3758 & ASTM D5489)

ISO 3758 & ASTM D5489 Garment Care Symbol & Bleaching Chemistry Reference

The five pictograms stitched onto a garment’s care label are not arbitrary suggestions—they represent standardized engineering limits defined by ISO 3758:2023 (international/GINETEX) and ASTM D5489 (North America) in a fixed five-symbol sequence: 1. Washing (Tub), 2. Bleaching (Triangle), 3. Drying (Square), 4. Ironing (Iron), and 5. Professional Textile Care (Circle). Misreading two diagonal lines inside a bleach triangle or a single bar beneath a wash tub is a leading cause of permanent dye loss, spandex degradation, and wool shrinkage. Filter all 38 official care symbols below or consult the complete static reference table.

Filter the 38 ISO 3758 & ASTM D5489 garment care symbols

Search symbol shape, dot count, letter, or temperature:
Care symbol category (ISO sequence 1–5):

Showing all 38 international and North American garment care symbols.

Pictogram Code	Symbol Name & Modifier	Category	ISO 3758 / ASTM D5489 Meaning	Exact Temperature / Limit	Textile Polymer & Chemical Engineering Rationale
`[Tub]`	Wash Tub (No Bars, No Dots)	`Washing`	Machine wash normal agitation	`Up to 60–95°C unless limited by dots/number`	Standard cotton, linen, and durable synthetics; full mechanical drum action and normal spin.
`[Tub • / 30°]`	Wash Tub + 1 Dot (or 30°)	`Washing`	Machine wash COLD	`Max 30 °C (86 °F)`	Protects dark reactive dyes from bleeding, wool/silk from thermal shock, and blood/protein stains from coagulating.
`[Tub •• / 40°]`	Wash Tub + 2 Dots (or 40°)	`Washing`	Machine wash WARM	`Max 40 °C (104 °F)`	Optimal catalytic temperature peak for subtilisin protease, amylase, and lipase enzymes without shrinking cotton-poly blends.
`[Tub ••• / 50°]`	Wash Tub + 3 Dots (or 50°)	`Washing`	Machine wash HOT-WARM	`Max 50 °C (122 °F)`	Melts solidified human sebum waxes (>38°C) and activates non-TAED sodium percarbonate oxygen bleach.
`[Tub •••• / 60°]`	Wash Tub + 4 Dots (or 60°)	`Washing`	Machine wash HOT (Sanitize/Bedding)	`Max 60 °C (140 °F)`	Thermal eradication threshold for dust mites (Dermatophagoides) and body-oil removal on colorfast cotton sheets and towels.
`[Tub 95°]`	Wash Tub + 5/6 Dots (or 70°/95°)	`Washing`	Machine wash BOIL / Heavy Sanitize	`Max 95 °C (203 °F)`	Unbleached or white 100% cotton/linen hospital and kitchen linens only; destroys elastane and shrinks wool.
`[Tub _ ]`	Wash Tub + 1 Underline Bar	`Washing`	Permanent Press / Mild Process	`Per dot/number rating`	Reduces drum mechanical agitation and uses a cool-down rinse + slow spin (400–600 RPM) to prevent setting wrinkles in thermoplastic polyester/nylon.
`[Tub == ]`	Wash Tub + 2 Underline Bars	`Washing`	Delicate / Gentle / Wool Cycle	`Typically 30 °C (86 °F)`	Minimal cradle-rock drum agitation (<20% duty cycle) and low spin to prevent wool cuticular scale ratchet felting and rayon wet tearing.
`[Tub + Hand]`	Wash Tub + Hand Icon	`Washing`	Hand Wash Only	`Max 40 °C (104 °F), prefer 30 °C`	Submerge gently in neutral pH 6–7.5 syndet bath; never wring or twist wet silk, cashmere, or structured lace.
`[Tub ✕]`	Wash Tub Crossed Out (X)	`Washing`	Do Not Wash in Water	`No aqueous immersion`	Aqueous swelling ruins structured wool interlinings (tailored suit jackets), crinkles crepe, or bleeds water-soluble finishes; dry clean only.
`[Twist ✕]`	Twisted Garment Crossed Out	`Washing`	Do Not Wring	`N/A (Mechanical limit)`	Never twist wet knitwear or rayon by hand; press water out flat between two dry terry bath towels.
`[ Δ ]`	Empty Triangle (Open Δ)	`Bleaching`	Any Bleach Allowed (When Needed)	`Cold–Warm dilution`	Permits either sodium hypochlorite (NaOCl chlorine bleach) or sodium percarbonate (oxygen bleach); still prefer oxygen bleach to preserve cotton tensile DP.
`[ Δ // ]`	Triangle with 2 Diagonal Lines	`Bleaching`	Non-Chlorine (Oxygen) Bleach Only	`40–60 °C (104–140 °F)`	Permits sodium percarbonate (2Na₂CO₃·3H₂O₂) or hydrogen peroxide (H₂O₂) ONLY. Strictly forbids NaOCl chlorine bleach (which strips dyes and degrades spandex).
`[ Δ CL ]`	Triangle with 'CL' Inside (Legacy)	`Bleaching`	Chlorine Bleach Permitted (Obsolete ISO)	`Cold dilute soak`	Superseded in ISO 3758:2012/2023 by the open triangle; indicates fabric resists dilute hypochlorite.
`[ ▲ ✕ ]`	Solid/Shaded Triangle Crossed Out	`Bleaching`	Do Not Bleach (No Chlorine or Peroxide)	`Zero oxidizers`	Fabric or dye is oxidation-sensitive (wool, silk, cashmere, elastane, or fugitive plant/indigo dyes). Use enzyme or solvent stain treatments only.
`[ □○ ]`	Square with Circle Inside	`Tumble Drying`	Tumble Dry Allowed (Normal)	`Any heat unless limited by dots`	Garment tolerates mechanical tumbling in a heated rotating drum.
`[ □○ • ]`	Square + Circle + 1 Dot	`Tumble Drying`	Tumble Dry LOW Heat (Delicate)	`Max exhaust temp 50–55 °C (125–131 °F)`	Prevents thermal shrinkage in cotton knits and prevents polyurethane oxidation in elastane/spandex activewear.
`[ □○ •• ]`	Square + Circle + 2 Dots	`Tumble Drying`	Tumble Dry MEDIUM / Normal Heat	`Max exhaust temp 65–70 °C (150–158 °F)`	Standard setting for cotton towels, sheets, and durable synthetic blends.
`[ □○ ••• ]`	Square + Circle + 3 Dots	`Tumble Drying`	Tumble Dry HIGH Heat (ASTM)	`Max exhaust temp 80 °C (176 °F)`	Heavy 100% cotton canvas or denim only; accelerates microfiber shedding and elastic fatigue if overused.
`[ □● ]`	Square + Circle (Solid/Black)	`Tumble Drying`	Tumble Dry NO HEAT / Air Fluff	`Ambient room air (20–25 °C)`	Uses mechanical drum tumbling with heating elements off to fluff down pillows or dust heat-sensitive items.
`[ □○ _ ]`	Square + Circle + 1 Bar Below	`Tumble Drying`	Tumble Dry Permanent Press	`Medium heat + extended cool-down tumble`	Slows cooling rate across glass-transition temperature (T_g ≈ 70–80°C for polyester) so creases do not lock in.
`[ □○ == ]`	Square + Circle + 2 Bars Below	`Tumble Drying`	Tumble Dry Gentle / Delicate	`Low heat + reduced drum cycle`	Minimizes mechanical abrasion on delicate weaves.
`[ □○ ✕ ]`	Square + Circle Crossed Out	`Tumble Drying`	Do Not Tumble Dry	`Air dry only`	Tumble drying causes catastrophic relaxation + felting shrinkage in wool, melts heat-sensitive coatings, or cracks rubber/PU prints.
`[ □ \| ]`	Square with Curved Top Line (or Vertical Line)	`Natural Drying`	Line Dry / Hang to Dry	`Ambient air`	Hang from clips or rounded hanger; vertical gravity pulls minor damp creases out of woven shirts and trousers.
`[ □ — ]`	Square with 1 Horizontal Line	`Natural Drying`	Dry Flat (Horizontal Surface)	`Ambient air`	Mandatory for heavy wet wool, cashmere, and rayon sweaters so water weight does not stretch shoulder seams downward.
`[ □ \|\|\| ]`	Square with 3 Vertical Lines	`Natural Drying`	Drip Dry (Hang Soaking Wet)	`Ambient air, zero spin/wring`	Hang directly from rinse bath without spinning so water weight aligns stiff or pleated synthetic drapery/garments.
`[ □ // ]`	Square with 2 Diagonal Corner Lines	`Natural Drying`	Dry in the Shade (Away from Direct Sun)	`Avoid UV-A/UV-B`	Prevents UV photolytic yellowing of wool keratin/silk fibroin and fading of fugitive natural or acid dyes.
`[ Iron ]`	Iron Icon (No Dots)	`Ironing`	Iron at Any Temperature (Steam or Dry)	`Up to 200 °C (392 °F)`	General pressing permitted.
`[ Iron • ]`	Iron + 1 Dot	`Ironing`	Iron LOW Temp (Cool Iron, No Steam)	`Max soleplate 110 °C (230 °F)`	Nylon, acrylic, acetate, elastane, and silk subsets; steam is prohibited at 110°C because water spits out as hot liquid droplets.
`[ Iron •• ]`	Iron + 2 Dots	`Ironing`	Iron MEDIUM Temp (Warm Iron)	`Max soleplate 150 °C (302 °F)`	Wool, silk, polyester, and viscose rayon; use a damp cotton pressing cloth over wool and dark fabrics to prevent shiny glazing.
`[ Iron ••• ]`	Iron + 3 Dots	`Ironing`	Iron HIGH Temp (Hot Steam Iron)	`Max soleplate 200 °C (392 °F)`	100% cotton, linen, and hemp; high steam plasticizes cellulose hydrogen bonds for crisp pressing.
`[ Iron ÷✕ ]`	Iron with Steam Lines Crossed Out	`Ironing`	Iron Dry Only — Do Not Steam	`Per dot rating`	Steam moisture causes water-spotting on silk taffeta, shrinks crepe viscose, or delaminates fusible collar interlinings.
`[ Iron ✕ ]`	Iron Crossed Out (X)	`Ironing`	Do Not Iron	`No hot soleplate contact`	Melts polypropylene/modacrylic pile, crushes velvet/corduroy nap, or blisters plastisol screen prints.
`[ (P) ]`	Circle with Letter 'P'	`Professional Care`	Professional Dry Clean (Perchloroethylene or Hydrocarbon)	`Non-aqueous solvent`	Tolerates tetrachloroethylene (PERC, Kb value ~90), hydrocarbon solvents, siloxane (GreenEarth), or high-solvency dry-cleaning fluids.
`[ (F) ]`	Circle with Letter 'F'	`Professional Care`	Professional Dry Clean (Hydrocarbon / Mild Solvent Only)	`Low-Kb solvent (Kb ~27–33)`	Sensitive beads, sequins, polyurethane coatings, or glues that dissolve in aggressive PERC must be cleaned in mild hydrocarbon or silicone solvent.
`[ (W) ]`	Circle with Letter 'W'	`Professional Care`	Professional Wet Cleaning	`Computer-controlled aqueous`	Uses specialized biodegradable acid/neutral surfactants, moisture-sensor drying, and tensioned steam formers as a non-solvent alternative for wool/silk.
`[ (P) _ ]`	Circle (P, F, or W) + 1 or 2 Bars	`Professional Care`	Professional Clean — Reduced Moisture & Mechanical Action	`Restricted cycle`	Instructs the dry cleaner or wet cleaner to limit water addition, drum rotation speed, and drying cabinet temperature.
`[ ○ ✕ ]`	Circle Crossed Out (X)	`Professional Care`	Do Not Dry Clean	`No organic dry-cleaning solvents`	Organic solvents (PERC/hydrocarbon) strip down feather oils, dissolve PVC/polyurethane faux-leather coatings, or melt polystyrene beads.

1. The Universal Dot & Underline-Bar Grammar Across ISO 3758 and ASTM D5489

Once you memorize two structural modifiers—Internal Dots (`•`) for thermal energy and Horizontal Underline Bars (`_`) for mechanical stress—you can decode any care tag in seconds without looking up individual icons:

Internal Dots (`•`) Govern Maximum Temperature: Whether placed inside a wash tub, a tumble-dryer circle, or an iron soleplate, more dots always mean higher heat. In the wash tub (ASTM D5489), `1 dot = 30 °C (86 °F, Cold)`, `2 dots = 40 °C (104 °F, Warm)`, `3 dots = 50 °C (122 °F)`, and `4 dots = 60 °C (140 °F, Hot)`. Inside the iron icon (both ISO and ASTM), `1 dot = 110 °C (230 °F)` (below the melting/softening threshold of nylon and acrylic), `2 dots = 150 °C (302 °F)` (safe for polyester, wool, and silk before scorching), and `3 dots = 200 °C (392 °F)` (required to relax hydrogen bonds in cotton and linen).
Horizontal Underline Bars (`_` vs. `==`) Govern Mechanical Shear & Spin Speed: Placed directly beneath a wash tub, tumble dryer, or professional cleaning circle, **no bar** means normal mechanical action; **one bar (`_`)** means *mild/permanent-press action* (reduced drum agitation + slow cool-down spin to avoid setting creases above a synthetic fiber’s glass transition temperature, `T_g`); and **two bars (`==`)** mean *very mild/delicate action* (minimal cradle agitation to prevent wool scale felting; see Wool & Cashmere Felting Mechanics).

2. Decoding the Three Bleach Triangles: Why Two Diagonal Lines Save Spandex and Dyes

The second symbol on every care tag—the **Triangle (`Δ`)**—governs oxidative bleaching chemistry. Confusing an open triangle with a striped triangle can destroy a garment in a single wash cycle:

Open Empty Triangle (`Δ`): Permits both **sodium hypochlorite (`NaOCl`, liquid chlorine bleach, `E° = +0.89 V` in alkaline solution)** and **sodium percarbonate (`2Na₂CO₃ · 3H₂O₂`, oxygen bleach)**. Even when an open triangle appears on a 100% white cotton shirt, textile chemists recommend oxygen bleach for routine whitening because repeated `NaOCl` exposure oxidizes cellulose C2/C3/C6 hydroxyl groups into carbonyl and carboxyl groups (*oxycellulose*), yellowing the fabric over time and cutting tensile strength.
Triangle with Two Diagonal Lines (`Δ //`): Means **Non-Chlorine (Oxygen) Bleach Only**. Why do almost all modern athletic shirts, stretch jeans (`98% cotton / 2% elastane`), and colored cottons carry this symbol? Because **hypochlorite (`OCl⁻`) attacks the urethane linkages of elastane (spandex/Lycra)**, causing immediate loss of stretch recovery, whereas the **perhydroxyl anion (`HOO⁻`)** released by sodium percarbonate (`OxiClean`) oxidizes polyphenol and tannin stain chromophores without cleaving polyurethane or reactive cotton dyes. Compare their exact redox potentials and `pH` curves in Sodium Percarbonate vs. Sodium Hypochlorite: Oxygen vs. Chlorine Bleach pH.
Solid Crossed-Out Triangle (`▲ ✕`): Prohibits **all oxidative bleaches** (both chlorine and oxygen/peroxide). Appears on protein fibers (wool, cashmere, silk), unstable natural dyes, and garments with water-repellent fluoropolymer/silicone DWR finishes.

3. Professional Solvent Chemistry: Why `(P)`, `(F)`, and `(W)` Are Not Interchangeable

When a care label displays a circle (`○`), it specifies the **Kauri-Butanol (`Kb`) solvency power** and polarity of the fluid a professional cleaner may use:

Circle `P` (`Perchloroethylene` or Equivalent): Tetrachloroethylene (`C₂Cl₄`, `PERC`) is a high-solvency chlorinated hydrocarbon (`Kb ≈ 90`) that dissolves heavy sebum, waxes, and oils effortlessly at `30 °C` without swelling hydrophilic wool or viscose fibers (thus preventing water shrinkage).
Circle `F` (`Flammable / Hydrocarbon` or Silicone Solvent Only): Synthetic leather trims, polystyrene sequins, pigment-printed fabrics, and bonded interlinings dissolve or blister in high-solvency `PERC` (`Kb 90`). Circle `F` restricts the cleaner to gentle **isoparaffinic hydrocarbon solvents (`DF-2000 / EcoSolv`, `Kb ≈ 27–32`)** or **decamethylcyclopentasiloxane (`D5` GreenEarth silicone, `Kb ≈ 13`)**.
Circle `W` (`Professional Wet Cleaning`): Indicates the garment is engineered for computer-controlled aqueous wet cleaning using low-pH protein-safe surfactants, anti-swelling sizing agents, and tensioned steam finishing forms. Cross-check specific stain treatments for any care-labeled fabric in our 28-Stain × Fiber Safety Lookup Matrix.