I run an after school program that teaches engineering to kids, mainly Kindergarten through 3rd grade (roughly ages 5 - 9). I'm trying to educate my coaches as to the known safety risks regarding using LEGO bricks, so that they can be forewarned and can take steps to avoid them. I think reading about specific, known cases, would be most helpful, along with any non-obvious preventative measures.

Anything that applies to class-safety would probably apply to home safety, too.

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    When I asked this question, I was finishing up a blog entry on the topic, which incorporated some of the answers given here. You can see the final article here: ascendly.com/page/…
    – ascendlyJJ
    Commented Jul 20, 2012 at 1:23
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    Also, wear shoes at all times.
    – Joubarc
    Commented Jan 15, 2013 at 8:38

5 Answers 5


The most obvious risk is swallowing parts, even though at that age it's probably less likely to happen. Magnets are the most dangerous, but LEGO has done a good job of hiding them recently.

Projectiles are also a risk, whether they are intended as such or not. Actual LEGO lauching machanisms (zamor spheres launchers, for example) can be quite dangerous and there's always an icon in the instructions to warn children of that risk.

Electrical parts can be hazardous, in particular if liquids are close. Although LEGO does a good job of protecting its parts (I've heard PF motors run wel even underwater), be particularly careful of mains adapters.

Spinning parts. It's fun, until you pinch you finger between two fast-spinning gears. Why do you think the saw blade first introduced with exo-force doesn't have a cross axle hole?

Pointy parts. LEGO tries to make them as soft as possible nowadays, or rubbery when possible.

And then there's the possible frustration of not being able to make the exact same creation that you have in mind.

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    Is the electric hazard a real and documented hazard, or more of a perceived hazard? I'm just sort of wondering if the voltage is ever high enough to cause any actual damage.
    – ascendlyJJ
    Commented Oct 28, 2011 at 18:54
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    Electricity is such a minor issue. Kids won't get hurt unless they strip the wires and jam them through the skin into their chest next to their heart.
    – Pubby
    Commented Oct 28, 2011 at 19:02
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    Voltage is broadly unrelated to how dangerous electricity can be. darwinawards.com/darwin/darwin1999-50.html. That being said, Lego's conductive bricks are very carefully designed to avoid exposure to the current. Definitely be careful around mains adapters, but the standard conductive bricks probably don't require any more supervision than the launchers or old-style knight weapons do.
    – user23
    Commented Oct 28, 2011 at 22:08
  • Note: the fact you can't easily electrocute yourself with LEGO voltage doesn't necessarily mean you can't make sparks or start fires or something. Commented Oct 5, 2020 at 13:34
  1. Make sure the kids avoid separating pieces with their teeth. Give them some brick separator tools and teach them to use them.
  2. Sharing is very important! You don't want another kid bopping someone in the head because they stole their piece. If you don't have enough of a certain piece for everyone then don't include that piece.
  3. If using projectiles only use 1 missile at a time. Safer to go 1 at a time than having 50 at a time. Also remember that kids only need the "cannon" while designing, not the missile.
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    4. Never aim projectiles at anyone's face. Commented Oct 28, 2011 at 21:03

If possible, give the kids large, rimmed trays (or even the lids from storage boxes) to keep their loose elements in.

This will reduce the number of pieces that fall on the floor and get stepped, knelt or sat on.

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    I wonder how much of a risk there is to slipping on a brick? Especially considering most school have those very hard floors.
    – ascendlyJJ
    Commented Oct 28, 2011 at 17:43
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    My students often use a cafeteria tray. I introduced them, originally, to just keep the mess confined, sort of anchoring the activity, even if not everything stays on the tray. A tray has an added benefit of providing a hard surface for building on, useful with carpet.
    – ascendlyJJ
    Commented Oct 28, 2011 at 17:49
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    @Pubby8: You have obviously never stepped on the corner of a Lego brick in the middle of the night.
    – user23
    Commented Oct 29, 2011 at 19:40
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    A friend suggested this funny video on brick safety: facebook.com/…
    – ascendlyJJ
    Commented Oct 31, 2011 at 13:04
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    Direct link to above video instead of linking through Facebook, which is a privacy concern.
    – TRiG
    Commented Nov 1, 2011 at 20:41

Never fire bricks towards another persons face. There are certain sets that provide mechanisms to fire bricks such as the Agents: Gold Hunt set. The missiles are rubber tipped to minimise damage.

If your school students are tasked with a project that involves projectiles I'd make sure they wear safety goggles, Especially if it involves non-lego parts or motors.


Don't lift too many bricks at one time. Being slightly older, I find a bag full of bricks can actually get heavy. I recently pulled a back muscle lifting a bag of 9,000 bricks. Hmmm, need to lift with my knees!

Granted, most people won't encounter this problem, I'm just saying....

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    Why is this getting downvoted. A down-vote without an explanation is very discouraging.
    – ascendlyJJ
    Commented Oct 29, 2011 at 17:07

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