# How do technicians treat spilt mercury and bromine?

As we know, mercury and bromine are in liquid state at room conditions and they are hazardous. The technicians should have ways to treat them if they are spilt.

How can we safely treat spilt $\ce{Hg}$ and $\ce{Br}$?

I have thought of using dry ice to cool the mercury down into a solid, which can then be easily removed. But I do not think that this is really practical. Maybe some chemical reactions can help to somehow convert the them into a solid in order to remove them.

• Do you mean spilt instead of split? – f'' Jul 20 '16 at 1:59
• Split mercury could be dangerous! I'd read an msds on the materials involved before I was using them and work out a plan of action from there. – Technetium Jul 20 '16 at 6:47

Any reputable chemical supplier will normally sell a mercury spill kit, and anyone working with mercury these days should have one. (Either a commercially prepared one, or an equivalent one that's assembled from individual supplies.) Generally speaking, they contain some sort of absorbent/adsorbent to pick up mercury, and a chemical which will react with the mercury and keep it from volatilizing. Sulfur is a common choice (recommended by the EPA), as mercury sulfide is pretty darn inert, as well as being very insoluble in water. (Also, "flowers of sulfur" does double duty as an absorbent.)

After the cleanup, the absorbent is collected (by sweeping - vacuuming can spread mercury vapors), packaged securely, and sent to a hazardous waste disposal company.

As elemental bromine is less widely used than elemental mercury, designated spill kits for bromine are less widely available, but the procedure is generally the same: spread a chemical to react with the bromine and render it more inert, then spread an absorbent to contain the liquid. Elemental bromine is rather reactive (an oxidizer), so a number of common reducing agents can be used. A 5% solution of sodium thiosulfate is a common choice (1) (2).

Again, if you're working with elemental bromine, your lab should have a spill response kit already assembled, with sufficient pre-prepared sodium thiosufate and absorbent to handle the amount of bromine you normally deal with.

The previous was for general information purposes only. If you are looking to work with elemental mercury or bromine, consult with your institution's chemical safety officer before purchasing for more information and restrictions which may apply in your area. Your institution likely also has chemical safety and spill response training, which will inform you of current best practices in handling mercury and bromine spills.

As always with accident handling, the most important thing is not to put yourself in greater danger by attempting to fix it. If the size or extent of the spill is such that you're unsure you can handle the spill safely, the best course of action is to evacuate the premises and let the hazardous materials team do the cleanup. (They'll likely use the same techniques of reacting and absorbing the material, but they'll be wearing more extensive personal protective equipment while doing it.)

• Mercury has been removed from practically any modern laboratory since ten years, but bromine is absolutely elementary for organic cemistry, every second year student does bromination reactions! But yes, thiosulfate solution. A large, freshly prepared beaker of thiosulfate solution. Never seen a "spill kit". – Karl Oct 3 '16 at 11:12

First, spilled mercury and bromine are emergencies. If this is happening to you - inform colleges and call specialists.

Second, Mg is magnesium, Hg is mercury.

Bromine is very volatile and irritating. It can kill or injure people very fast. If small amount was spilled - leave the open windows, leave the room, close doors, wait. If spilled one someone (this is a real emergency) you should apply 95-100% ethanol to the injured part of the body. This method helps the best.

Hg is chronically toxic (acute toxicity of metallic mercury is low). You can absorb it on iron iron chloride (III) powder to absorb Hg or apply sulfur to the area of the spill.

Mg is relatively safe and can be collected with with a floor mop.

• @The worst , what about the 'split' ? – Technetium Jul 20 '16 at 6:49
• > iron dust || mercury does not adhere iron. Copper wire should be used. – permeakra Jul 20 '16 at 7:21
• Iron does not dissolve in mercury, so this procedure is useless. And mixing iron dust with sulfur is dangerous, it can result in a fire! – vapid Jul 20 '16 at 7:29
• Also, in case of skin contact with bromine, use a lot of water to wash it, not ethanol! Ethanol may cause the bromine to penetrate deeper into the skin causing more severe burns! – vapid Jul 20 '16 at 7:37
• Well I didn't spill bromine on myself, probably because I always familiarize myself with msds's. There is a general rule that you never use organic solvents to treat chemical burns. In case of bromine I would use solution of sodium bicarbonate. Some msds's suggest also soap water in that case. Yes, ethanol may seem to work if you have bromine absorbed only on your epidermis, because the alcohol will extract it. But for deeper burns it will only worsen things. – vapid Jul 21 '16 at 7:22