So we were climbing today with some friends and an accidental liquid chalk explosion occurred in one of the backpacks. Contents of said backpack include: carabiners, a nylon sling and the nylon climbing rope. I am wondering if someone can share experience on the relative safety of continual use with said items. Obviously a wash before use, but that aside, is it possible that i may have retire the gear?

1 Answer 1


Climbing chalk is almost always magnesium carbonate (MgCO3; source: ClimberNews). Liquid chalk is just a suspension of magnesium carbonate in a low vapour pressure liquid, something like acetone or ethanol, which will evaporate quickly and leave you with dry chalk on the hands (and significantly cooler hands too, much like hand sanitizers).

Magnesium carbonate is pretty much insoluble in water (~0.01g MgCO3/100 ml water), so rinsing in water will only wash away the particulates that are loosely attached and not sheltered from the flow of water. This would be a good first step to remove bulk contamination, but it certainly won't get rid of it all. About the only easily obtained method of dissolving MgCO3 is in weak acidic solutions - dilute vinegar will work. Most of your plastic-based gear (e.g. nylon) should be resistant to a dilute solution of vinegar, although metals (particularly aluminium) might be attacked to some extent.

Magnesium carbonate has a hardness of 3.5-4.5 on the Mohs hardness scale, which is harder than that of aluminium (2.75), so small particles of magnesium carbonate could wear away at your aluminium gear, but won't affect titanium (Mohs 6.0). However you can wash metal gear fairly aggressively with water and a brush to remove almost all the particulates, and any remaining contamination is likely to be less than you might naturally acquire during climbing with chalk anyway.

With respect to the rope, I would be a little concerned about particles inside the fibers of the rope causing some sort of wear, but I don't know how this would affect the safety of said rope. Perhaps your local climbing store would have a better idea?

  • I think OP could wash the rope in a machine, but it may shrink by a few metres.
    – Darren
    Sep 4, 2020 at 3:56
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    I would not be too concerned about the chalk in the rope. While it may cause some wear, there is also a lot of dirty and chalk rubbed into the rope in normal use, especially at the ends where climbers touch it with chalked up hands. It does not hurt though to wash the rope. Instructions differ slightly for various manufacturers but most allow waschine with a soft detergent in the maschine. I personally prefer to wash the rope manually in the bath tub. Give the rope enough time to dry (~1 week) and do not dry it in the sun (unnecessary UV exposure)
    – Manziel
    Sep 4, 2020 at 7:38
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    @Manziel I’m not sure how concerned I’d be about any of the kit TBH. I’d say by all means rinse it off, but if liquid chalk was in any way dangerous to climbing gear they wouldn’t sell it. Imagine the court case when a climber dies due to malfunctioning equipment and they try to blame the fact they’ve been handling it with liquid chalk on their hands.
    – Darren
    Sep 4, 2020 at 8:40
  • Thank you for your comments. I will thoroughly wash everything and watch meticulously for any additional ware and tare. Just fyi i found this other post online that seems to point in the same direction: mountainproject.com/forum/topic/119061233/is-liquid-chalk-safe
    – Momchill
    Sep 4, 2020 at 10:19
  • @Momchill - good point in that link - I didn't think about the potential solvent problem with liquid chalk and plastics.
    – bob1
    Sep 5, 2020 at 9:45

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