Iron on low (one dot)
One dot allows ironing up to 120°C under ISO 3758:2023 or 110°C under ASTM D5489.
What to do
Use the one-dot low setting. Stay at or below 120°C on a current ISO label or 110°C on a US ASTM label.
What to avoid
The ISO 120°C and ASTM 110°C limits are maxima, not targets. If the standard is unclear, use 110°C.
How to spot it on a label
Ironing is the fourth family in the standard label order, after the drying symbol. Confirm the low-temperature variant by finding one dot inside the iron body, not underneath it. Two strokes crossing over the whole iron would make it a prohibition instead. The one dot sets a 120°C maximum under current ISO 3758:2023 or 110°C under ASTM D5489.
Easy to confuse with
- Iron on low (one dot)Iron, any temperature
Check the mark
Look directly inside the iron. This symbol has one dot; the plain any-temperature iron has an empty body.
- Iron on low (one dot)Iron on medium (two dots)
Check the mark
Count the dots inside the iron body: one, not the two shown for medium temperature.
- Iron on low (one dot)Iron without steam
Check the mark
Check both places. A one-dot iron with nothing below it is the low-temperature mark. Current ISO no steam adds crossed lines below that one dot, while the ASTM no-steam version has a blank body.
On a real label
Silk scarf
Read together: Hand wash, do not bleach, dry flat, use the one-dot low iron setting, and use a professional cleaner that follows the P-solvent instruction if dry cleaning is needed.
Acrylic knit cardigan
Read together: Use a delicate machine cycle, do not bleach, dry flat, use no more than the one-dot iron setting, and do not dry clean.
- Category
- Ironing
- Appears on
- US and international labels
Related symbols
Common questions
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What temperature is one dot on an iron?
- One dot sets a maximum sole-plate temperature of 120°C under ISO 3758:2023 or 110°C under ASTM D5489. Do not go hotter than the standard that applies to the label.
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Do I have to iron at the one-dot maximum?
- No. The limit is a ceiling, not a required setting. You can use a cooler setting and still follow the symbol.
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Can I iron silk?
- If that silk item's label shows one dot, ironing is permitted up to 120°C under current ISO or 110°C under ASTM. Check the individual tag rather than assuming every silk item has the same instruction.
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What is the difference between one dot and two dots on an iron?
- Current ISO sets one and two dots at 120°C and 160°C. ASTM sets them at 110°C and 150°C. Count the dots, then stay at or below the limit for the label's standard.