Is it possible to spread a chemical or the danger of a chemical if the chemical has dried up on a piece of paper? For example if in a lab I have gotten a certain chemical on my lab paper but the chemical has dried up does that lab paper now pose a threat to my health and the health of others? Also if after touching the lab paper I touch my jacket and then after touching my jacket I eat something later on would I be in danger?

The chemical I am referring to is copper sulfate.

I have not experienced any irritation or burns (maybe some weird stomach or digestive problems).

Thank you


closed as too broad by ringo, Todd Minehardt, Jon Custer, Freddy, Geoff Hutchison Apr 12 '16 at 18:13

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • 5
    $\begingroup$ Yes, depending on the chemical of course. $\endgroup$ – Jon Custer Apr 11 '16 at 19:25
  • 3
    $\begingroup$ No offence, but you should not work in a laboratory if you ask questions like this, and your supervisor ought to be hanged for letting you. You are a danger to the health and safety of everyone around you, including yourself. Unless all the chemicals around you are indeed totally harmless, which I can't know, but doubt. Get your supervisor to give you a thorough safety briefing, and try to learn some basic chemistry. $\endgroup$ – Karl Apr 11 '16 at 20:20
  • 1
    $\begingroup$ I second Karl's comment. Think about it. This is your only life. $\endgroup$ – Ivan Neretin Apr 11 '16 at 23:07
  • 3
    $\begingroup$ @Karl, I understand you sentiment completely, but it could have been phrased less harshly. $\endgroup$ – jonsca Apr 12 '16 at 0:22
  • 2
    $\begingroup$ Always remember: the sign of a true chemist is that they wash their hands before going to the toilet. $\endgroup$ – matt_black Apr 12 '16 at 15:40

There is no sensible single answer to this: it depends on the chemical (and you really should read the safety notes before using anything or you will cause severe trouble.)

Consider these scenarios.

You are working with a solution of common salt and you spill it on your lab coat. No problem at all; you could eat your dinner off the lab coat as it is the same slat you might sprinkle on food. But you spill a solution containing some mercury salts on your coat, get it cleaned and decontaminated immediately as it will eventually poison you even if you don't use it to wrap your dinner.

Or you spill some ether on your lab coat. Don't stand near naked flames until it has evaporated, but once it has gone, it has gone with no lingering effects. Spill some nitric acid/sulphuric acid mixtures on it and even if you wash it off before wearing it again you might still have the problem that it has created some nitrocellulose, which can spontaneously combust, taking you with it. Equally badly, you spill some tellurium salts on your coat. They might not kill you but you will be shunned for weeks as you will smell strongly of something like garlic, but more offensive.

Bottom line: read the safety instructions and act accordingly: there is no general rule.

  • $\begingroup$ I disagree, there is a general rule: Things that are done in a lab shall remain in the lab, no exceptions. Safety is number one priority! $\endgroup$ – Martin - マーチン Apr 12 '16 at 5:09
  • 1
    $\begingroup$ @Martin-マーチン this is a good rule, but insufficient. Just because your lab coat never leaves the lab doesn't make it safe (a contact poison on your coat will still poison you in the lab if you keep wearing it). $\endgroup$ – matt_black Apr 12 '16 at 10:40

What do you mean exactly with "dried up" ? Did you spill hydrochloric acid on your lab book, and you worry about the paper being corrosive by now ?

It is always best to know what you are dealing with and its reactivity. As rule, what belongs in the lab stays in the lab. This means lab books and labcoats. And washing your hands before eating. If you suspect something has been contaminated, the best thing is to treat it like hazardous waste, dispose of it accordingly, and do not bring it outside the lab/at home, etc. These are only basic safety measures. Stuff does not "disappear". If it evaporates, it goes somewhere else. If it reacts, you have another species to deal with. If the solvent evaporates, you are left with a product in the solid state, all the more reactive...

Can the danger/toxicity propagate to the products of a reaction ? Yes, eg., if you prepare a cyanohydrin using a toxic cyanide salt, you can still get cyanide poisoning if you are exposed to the cyanohydrin.

Ask your safety officer.


Not the answer you're looking for? Browse other questions tagged or ask your own question.