# 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 vary in temperature from -10 degrees Celsius to 25 degrees Celsius. The shed is outside my house. I also store my etchent next to HCL and hydrogen peroxide in the shed as well. Will it be safe to store all of these three chemicals inside a shed?

I do have metal tools in there but I don't care if it rusts. I am just afraid of hydrogen gas that might form because of HCL fumes. Also, I store my acetone indoor inside a plastic container because I heard that its flash point is -20 degrees Celsius. I don't want it to spontaneously catch on fire if I did store it in the shed. So are these storing method adequate or do I need more precautions.

• You probably have gasoline in the shed which is about as dangerous as acetone. 3% hydrogen peroxide can be bought in a drug store, so no biggie. The 10M acid is a problem to me. It probably is in a glass bottle. What if you knock something over in the shed which breaks the bottle? Since you're asking the question I seriously doubt you're taking the proper safety precautions. Also kids then to play around in sheds. So the shed needs to be locked at least. – MaxW Oct 15 '16 at 0:56
• PPE and ventilation are a must. Your info on acetone is way off - mine regularly withstands 40 Celsius (or higher). You'll get more expert advice that what I can offer here, but do be careful. Also: my glassware and all chemicals (including things like bug spray and the like) are in double-locked, explosion-proof cabinets. – Todd Minehardt Oct 15 '16 at 0:57
• I dont have gasoline in my shed and no one even comes in here anyway. The 10M acid is in a polyethylene jug not a glass bottle. Also the info about acetone's flash point is from MSDS. – steven Oct 15 '16 at 1:39
• Not a danger, but household 3% hydrogen peroxide slowly decomposes, and decomposes more rapidly when mixed with almost anything (phosphates being one exception). The peroxide's shelf life is limited, particularly once opened, or mixed with HCl, or with large temperature swings. Unless it takes up too much room, I'd store it in my house. – DrMoishe Pippik Oct 16 '16 at 2:44

I commend your extreme caution here in general, although your fears of the acetone igniting from sitting in a hot shed are unwarranted. The flash point of a compound is the lowest temperature at which it can be ignited with an ignition source, like a spark. This is commonly confused with the autoignition temperature, which is the lowest temperature at which a compound can spontaneously combust without an ignition source. So, while you really don't want your acetone near a flame or spark source at any temperature, it's autoignition temperature is $\pu{465^oC}$ and so you don't have to worry about it igniting just from sitting in a hot shed.