While erasing stuff written using a chalk on a blackboard, with a duster, it is commonly observed that a lot of chalkdust is released in to the air, some part of which is inhaled (largely) by the teacher, and sometimes, also the first/second row students. This can be a problem, since even if we discount the case of bad allergies from chalk-dust, this inhalation can cause coughing etc. which one would ideally want to avoid.

What is the best hack to ensure you inhale as little of chalk-dust as possible during this process?

(Of course, this problem does not apply to the relatively swankier marker-whiteboard version of the same, but that's not what this question is about.)

Here are a few hacks I seem to think off, but none of these is of the creative variety that one would ideally want as an ingenious solution to the problem:

  • Switch to a classroom with a marker-whiteboard arrangement. (Least creative resort, this isn't what I'm asking about here. This changes the condition of the question.)

  • Adopt "non-dust" chalk. (Doable, but still not the creative answer I'm anticipating.)

  • Turn up earlier than the class timings, and wipe the blackboard with a wet cloth, which would reduce the amount of chalk dust inherently existing on the board, even without you having written something. (This is doable, e.g. for the first class of the day. But when multiple classes cascade, i.e. one after another during the day, this is time-costly option, and hence, not very efficient.)

  • Go outside the classroom, and bump the duster on a flat surface, which would eliminate most of the dust it has procured from earlier, and hence, you are working with a lesser amount of chalkdust.

  • Tie a handkerchief on your nose and mouth while erasing it, to reduce the amount inhaled. (Perhaps the worst option, I mean, seriously ...!!!)

Is there any simpler strategy (i.e. lifehack) around this problem?

  • 1
    Decades ago when I was at school I remember that we always had to use a slightly wet sponge for wiping the board. This usually dried within a few minutes but we often made a joke and used a dripping wet sponge which left far too much water on the board. The teacher then could not write on it until it finally had dried out...
    – Takkat
    Apr 9, 2016 at 20:28
  • 2
    Vacuum cleaners and gas masks!!1! Why don't you just use a minimally wet sponge? I'm from Germany and that's what all my teachers did, never seen a lot of chalk dust. Apr 10, 2016 at 7:04
  • 1
    Disclaimer: This "answer" is overly silly. Write in a light color (white). Use a barely damp thing to "wipe" the board, really just smearing the blackboard into more of a "grayboard". Write with dark color chalk (your choice). Then just keep flipping back and forth between light and dark colors.
    – goodguy5
    Apr 11, 2016 at 13:50
  • @goodguy5 - Not really silly. That looks like some ingenuity to me. :)
    – 299792458
    Apr 11, 2016 at 17:00
  • 1
    same as other comments, almost all black boards at my schools and university have been cleaned with water. new text is much better readable (higher contrast) if there is no chalk dust left on the board. the wet blackboard is no problem if you remove the water with one of these window cleaning things: youtube.com/watch?v=NpQyp28VQZQ time loss for the two step cleaning doesn't matter in practise (micro break for students / catching up copying notes from the other board / time to think about question)
    – pseyfert
    Apr 18, 2016 at 18:20

5 Answers 5


Assuming you are not forced to use a duster, I'd suggest cleaning the boards with water in the following way:

There are special tools designed to clean windows one is called t-bar and squeegee.
You first make the mop reasonably wet, swipe over the board horizontally, beginning at the top and then going down (with slight overlap). Then you take the squeegee and dry it in the same pattern (also with slight overlap). This method is much faster (around 30s for 5m^2) than it sounds, I'd argue even faster than using a duster. My teachers regularly do this even during the lectures and it is not disruptive at all. The downside is that some water will run down the board, but most boards have a small sill to catch it; there it can be soaked up with a towel.

I'd suggest buying a rather large (~50cm) t-bar and mop and a smaller squeegee so you only have to apply reasonable force to get the necessary pressure.

  • Were you actually not aware of it?
    – caconyrn
    Apr 27, 2016 at 14:48
  • This does add the extra logistics of filling a bucket of water before class and emptying it afterward. Another note is that the effectiveness of a standard eraser (duster) relies in part on having a base layer of chalk dust - if you clean the board with water, the duster won't work as well. Particularly if you start writing again before the board is completely dry. May 2, 2016 at 21:48

Damp the eraser (traps dust), tape 2 together (double-wide, fewer swipes), be deliberate & precise not vigorous (don't 'kick up a storm'), and (maybe) swipe in one direction only, away from you, like a broom.

  • I like this, especially the last one. Thanks.
    – 299792458
    Apr 18, 2016 at 13:01

If you are ready to spend a bit use Apsara Dustless White chalk or any other dustless chalks.It reduce inhalation of harmful dust and also reduces the risk of skin allergies.


Tie a handkerchief on your nose and mouth while erasing it, to reduce the amount inhaled. (Perhaps the worst option, I mean, seriously ...!!!)

This could actually be the best idea! Get something cool / funny / trendy with the class demographic, and make a brief 'show' of donning the handkerchief and wiping the blackboard. The students might actually become more engaged!

You could go with a gator, maybe a ninja, a monkey, a superhero or any number of other things.

*edit: I'm not affiliated with that last link in any way - it as just the first result i found on google!

  • You could have a robot-style mask and wipe with robot-like movements, a zombie mask and zombie movement, "braaaaiiiiiinnnnnnnnssssssss" etc
    – Adam
    Apr 18, 2016 at 23:02

Rather than move the eraser from side-to-side, right-to-left, left-to-right; wipe from the top to the bottom. Move across the board repeating your movement from top-to-bottom only—lifting the eraser between each down stroke.

This one-way action will greatly reduce the airborne chalk dust. The bulk of the chalk dust will accumulate in the chalk tray which can be disposed of neatly into a receptacle at the conclusion of the class.

Practice makes perfect.


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