Questions tagged [safety]

Questions regarding chemical and lab safety. This includes questions about proper lab procedure, safe chemical handling, and such.

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74
votes
6answers
20k views

Do all salts taste salty?

Recently, I am learning the production of soluble and insoluble salts. My friend and I have done this experiment at the school lab. We wanted to taste them to see whether they are salty are not. The ...
90
votes
7answers
232k views

Is it actually possible to dispose of a body with hydrofluoric acid?

In the TV show "Breaking Bad", Walter White frequently gets rid of people who get in his way by submerging them in a plastic container full of hydrofluoric acid. This, at least in the TV show, ...
68
votes
5answers
17k views

How do people know HCN smells like almonds?

I was told by my chemistry teacher that $\ce{HCN}$ smells like almonds. She then went on to tell a story about how some of her students tried to play a prank on her by pouring almond extract down the ...
14
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4answers
29k views

How explosive is hydrogen gas?

I want to electrolyze water to get oxygen and hydrogen. I want to mix them in a regular balloon and ignite it. How much hydrogen would you need in a 2:1 ratio with air for it to be dangerous? Is this ...
9
votes
2answers
14k views

How does sulfuric acid react to heating?

How would $\ce{H2SO4}$ react to heat ? I assume that it would form toxic sulfur (di/tri)oxide, but I can't find any information on this. I'm concerned about fire hazards specifically, so assume very ...
55
votes
4answers
202k views

Why add water first then acid?

From school, I remember a very important rule: first you need to pour the water and then the acid (when you need to mix them) not vice-versa. This is because otherwise the aсid becomes very hot and ...
20
votes
3answers
12k views

Please explain why dioxygen difluoride is so dangerous

I just read this article that mentioned that dioxygen difluoride is very dangerous. The terms it uses are "awful", "violently hideous" and "deeply alarming". But I couldn't get a handle on exactly ...
28
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5answers
58k views

Acid Accident Treatment

What are the general ways to treat an accident involving highly concentrated or similarly dangerous acids? I have a lab instructor who recently debated with our group about treating an acid spill on ...
27
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2answers
3k views

How to properly store acids at home?

I bought different kinds of acid for experiments and home usage that I stored in secured containers into an IKEA cabinet. I just realized that despite the fact that all the containers are properly ...
14
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6answers
50k views

Handling and storing sodium hydroxide, hydrochloric acid, hydrogen peroxide and isopropyl alcohol

I'm an electrical engineering and I hope you can give me some advice as I'm not much into chemistry. I'm trying to start making my PCB (Printed Circuit Board) at home but I'd like to have some advice ...
7
votes
1answer
8k views

Do chemicals have an expiry date?

A bonus question would be, if so, why? Is it because it decomposes and hence the expiry date is calculated out?
17
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2answers
3k views

Why is use of calcium carbide as an artificial fruit ripening agent banned?

Fruits like mangoes can be ripened using agents like ethylene, acetylene or calcium carbide. Of these, the latter is dangerous and is banned in most countries. Wikipedia says it is because calcium ...
12
votes
3answers
9k views

How to remove a stuck stopper from a flask?

How do I remove a stopper that has been stuck in the neck of a 100 mL round bottom flask since I forgot to wipe the neck of the flask. A salt was formed in the 100 mL flask and the stopper ...
7
votes
1answer
1k views

Vacuum distillation apparatus selection and configuration

I want to assemble a "hobbyist-level" vacuum distillation apparatus for extracting small volumes of "typical" solvents (e.g., water, alcohols, ketones, diols). I already have standard lab glassware ...
5
votes
2answers
1k views

Can dimethylmercury originate from cleaning up a broken thermometer with disposable wet wipes?

I broke a CFL in my home (so elemental mercury is present in a small amount) and wiped up some of the mess with a clorox wipe. The wipe in question contains dimethyl benzyl ammonium chloride and ...
3
votes
1answer
911 views

Is Tollen's test safe?

Tollen's test is an important test to distinguish between aldehyde and ketone. $$\ce{2 [Ag(NH3)2]+ + RCHO + H2O → 2 Ag(s) + 4 NH3 + RCO2H + 2 H+}$$ But is this reaction safe? Is there any threat in ...
-1
votes
1answer
5k views

What could happen when mixing bleach with other cleaning residue?

I have a wall covered in mold. I have used various cleaning wipes attempting to clean it, including a vinegar mixture. I now want to spray the wall with a bleach cleaner. I am concerned for fumes from ...
40
votes
5answers
36k views

Is there any substance that's a 4-4-4 on the NFPA diamond?

A lot of the organometallics are rather... interesting compounds to work with. The most famous (among those who care, anyway) is tert-butyllithium or t-BuLi. It is the textbook example of a pyrophoric ...
32
votes
1answer
1k views

Flammability (NFPA) - how is it defined?

I was reading up on a wonderful little chemical compound known as chlorine trifluoride ($\ce{ClF3}$). For a primer, check out Dr. Derek Lowe's blog post here: Sand Won't Save You This Time. The title ...
3
votes
2answers
13k views

What are the effects of Lithium Dioxide on the body?

My question is about how much science-fiction and how much chemistry is involved in the the 'Randy's Donuts' scene of Iron Man 2: Agent Romanoff injects Lithium Dioxide into Tony Stark's neck to ...
14
votes
3answers
4k views

Practical safety of storing potassium

Potassium ($\ce{K}$) seems to be the transitional alkali metal in terms of safety. Lighter than $\ce{K}$ and we can store under oil with no worries. Heavier than $\ce{K}$ and only ampules will work. $\...
12
votes
2answers
214 views

Why do seemingly reliable sources give NFPA 704 Health ratings ranging from 1-4 for elemental mercury?

Recently a user posted the question Do Mercury have a NFPA 704 classification?. Why the present question is not a duplicate: Although there is no accepted answer to the above question, I think it's ...
12
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3answers
36k views

Does milk drinking prevent long-term chemical poisoning?

I have heard some rumors that drinking milk prevents chemical poisoning. I have done a bit research and some sources confirm that. Corrosive Poisons The best first aid is to dilute the poison ...
11
votes
2answers
7k views

Proper use of vacuum pump during vacuum distillation

I am preparing to do a vacuum distillation and am unsure exactly how to manage the vacuum. The vacuum pump I have is a two-stage rotary vane pump which is capable of 250 microns or lower. It has a ...
7
votes
3answers
2k views

Is there a type of detergent/surfactant that evaporates at STP?

Are there any type of detergent/surfactant chemicals that would be good for removing dirt and grease from fabric that also would evaporate from the clothes within, say, 24 hours leaving no residue? ...
4
votes
1answer
3k views

Reaction between a vinegar/salt/hydrogen peroxide mixture as an etching solution and copper

I am looking for the less harmful chemical solution to serve as an etching solution. After many searches, my interest went to a vinegar/salt/hydrogen peroxide solution. I have to ask then if the ...
2
votes
3answers
5k views

Is it dangerous to inhale the steam coming from electrolysis of salt-water solution [closed]

Is chlorine in there that accumulates (at the anode) and emerge out as chlorine gas? I was worried since I added a pinch of salt to the steamer in order to hasten the heating of tap water when I ...
2
votes
0answers
348 views

Hazardous materials handled by amateur chemists [closed]

I'm a enthusiastic and devoted amateur chemist (in disguise, I'm actually a mathematician), but lately I've been thinking to what extend it is safe to pursue my hobby. I'm after all an amateur with ...
17
votes
2answers
1k views

Safety in handling of concentrated ammonium fluoride

I recently saw a protocol for extracting organic materials that are bound in the silica matrix formed by diatoms. The extraction protocol used 10 molar ammonium fluoride ($\ce{NH4F}$). I briefly ...
16
votes
3answers
5k views

Why did the salt on the skin of my turkey react with the aluminum foil it was touching?

I sprinkled salt on my turkey skin and left it to dry out over night. It was covered with aluminum foil. The next morning the aluminum foil had holes ‘burnt’ in it and the turkey skin turned silver at ...
16
votes
2answers
18k views

How to properly dispose of sodium…or store it properly

While performing an inventory of my school's chemical storage closet today, my fellow teacher and I found some sodium tucked away in the back corner of our flammables cabinet. One container appears ...
12
votes
1answer
8k views

Why would sulfuric acid turn gray/black?

About 2 years ago I purchased 2 liters of 98% concentrated sulfuric acid. It's in a standard poly bottle with leakproof lids, and originally was clear. Recently I noticed the acids have turned a dark ...
12
votes
2answers
1k views

How does heptafluoropropane suppress fire?

How does heptafluoropropane suppress fire? It says here that it does so by "inhibiting the chain reaction." What does that mean specifically? Does $\ce{O2}$ attach itself to the heptafluoropropane?...
9
votes
2answers
3k views

Is there a way to contain fluorine gas for long term so that it can be visually observed?

Bromine, chlorine and iodine can all be sealed in a glass container for display without the elements reacting with the glass. But if you try to seal fluorine in glass I believe it will react and fog ...
7
votes
1answer
2k views

Is the Hollywood portrayal of the effects of ingesting HCN correct?

In the 2012 movie Skyfall, the antagonist Raoul Silva rues that the "hydrogen cyanide" he took ("Do you know what it does to you, hydrogen cyanide?") didn't kill him, leaving him horribly disfigured ...
7
votes
1answer
5k views

Best Fuel for Potato Gun

I have been using deodorant to propel potatoes (potato gun :D), but I want to switch over to pure butane. However, in order to do this safely I have to know how much butane is typically in deodorant (...
6
votes
1answer
6k views

How dangerous is cobalt(II) chloride used in silica gel balls?

I was looking up silica gel beads on Wikipedia and noticed that some (and from experience most) are doped with a colouring agent to indicate that they have absorbed all that they can. The Wikipedia ...
6
votes
3answers
10k views

Isopropyl alcohol forming peroxides

I read in many MSDS that Isopropyl alcohol tends to form peroxides (by reacting to air OR light) which may explode when they reach a given concentration. For example: http://nj.gov/health/eoh/rtkweb/...
5
votes
1answer
3k views

In practice, how dangerous is liquid oxygen as an oxidizing agent?

The Wikipedia page on liquid oxygen tells us Liquid oxygen is also a very powerful oxidizing agent [...], if soaked in liquid oxygen, some materials such as coal briquettes, carbon black, etc., can ...
3
votes
0answers
369 views

Brewing tea with deionized water

I am wondering what efect brewing tea (let us assume for the sake of simplicity it is green tea, brewed at about 80 °C) in deionized water might have on the product. Will the lack of ions in the ...
2
votes
2answers
5k views

Mixing bleach and ammonia?

I know that the two should not be mixed, but i want to know that if the two become mixed in a contained unit, does it build pressure? Or can you seal the container safely untill it can be disposed of ...
2
votes
2answers
925 views

Is it safe to store muriatic acid, hydrogen peroxide and acetone?

I am recently getting into PCB etching. So I use 10 M HCL solution, 3% hydrogen peroxide mixed in 1:1 ratio for my etchent. Currently, I am storing my HCL and hydrogen peroxide in my shed which can ...
2
votes
2answers
461 views

Does mercury have an NFPA 704 classification?

I've searched on a lot of websites if elemental mercury (Hg) has an NFPA classification but I can't find any. Does mercury have an NFPA classification?
2
votes
2answers
57 views

Lab goggle recommendations?

I'm taking my first chemistry class with a laboratory component this quarter. My first laboratory session was earlier this evening (observing simple metathesis reactions). While I found the lab work ...
2
votes
1answer
10k views

How do I store HCl safely?

I'm in a textile unit, where we use different chemicals. My question is what type of material should I make my tank out of to store my hydrochloric acid?
1
vote
1answer
223 views

Where to store Sodium Azide?

I have about 100g of Sodium azide and would like to store it properly. Any suggestions as to where? I though of storing it in a locked vault but there are chemicals such as Arsenic sulfide, aniline, ...
1
vote
2answers
604 views

Can caffeine be separated from coffee?

Is there a way to extract caffeine from coffee completely?
1
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2answers
2k views

Under which criteria HNO3 is a concentrated or a diluted acid? [closed]

I would like to buy nitric acid to remove impurities of copper on an aluminum plate. I read that a 10% nitric acid will do the job. However I've also read that concentrated nitric acid is very ...
1
vote
1answer
6k views

How to produce dry pure oxygen

I'm supposed to produce dry and pure oxygen using the decomposition of hydrogen peroxide with a manganese dioxide catalyst. $$\ce{2H2O2 (aq) → 2H2O (l) + O2 (g)}$$ The gas will be collected in a ...
0
votes
0answers
65 views

Highly concentrated NaOH solution at high temperature vs borosilicate glassware and cellulose?

I've read here on stack-exchange that NaOH will react with glass through the following reaction: 4 NaOH + SiO2 ⤑ Na4SiO4 + 2 H2O I would like to briefly heat a highly concentrated NaOH solution to ...