Hydrogen Peroxide decomposition data

[rjche]

Those working with HP need to know how much it deteriorates with time.

This data is from a HP mfg page. It states deterioration is about 1% per year.

It also gives data on the usual type HP avaiable to experimenters.

Note that this technical grade may contain some non organic stabilizing chemicals. Nothing more is said about that.

(In my opinion is they would be trivial quantities, and apparently from its successful use for AP production, they have not shown any interference.)

The MFG data:
-------------------------------------

Technical Grade hydrogen peroxide is used in the pulp and paper industry in bleaching chemical and mechanical pulp and in waste paper recycling. In the textile industry, it is a bleach for natural and synthetic fibers and a desizing agent. It also safely detoxifies many industrial wastes,including phenolics and reduced sulfur compounds. Technical Grade hydrogen peroxide is also used in the extraction and finishing of metals.

Technical Grade hydrogen peroxide is also available in concentrations of 35% and 50% in truckload drum shipments. Less than truckload shipments of hydrogen peroxide are available from distributors.

(Small (gallons) amounts are available from local chemical supply houses. Last I bought was about $usa 10 per gallon 50%)

Physical Properties: Hydrogen peroxide is a clear, colorless, slightly viscous liquid. It is slightly denser than water but is miscible with water in all proportions. Hydrogen peroxide decomposes exothermally to water and oxygen with no toxic residues.

The decomposition is normally slow (<1%/yr) with no temperature rise but is accelerated by heat and decomposition catalysts, such as transition metals and their compounds, strong acids and strong alkalis.

Typical Analysis 35% 50% 70% Concentration in water,
Appearance Clear, colorless

Storage and Handling* Store hydrogen peroxide in the original vented container, upright, in a cool, ventilated area where it is protected from damage.

Water is the preferred method for extinguishing fires in which hydrogen peroxide is present.* Spills and leaks should be contained, diluted with copious amounts of water.

First AidIn case of product splashing into the eyes and face, treat eyes first.

Eye contact:Flush eyes immediately with water for at least 15 minutes. Call a physician.

Skin contact:Immediately flush skin with water while removing contaminated clothing andshoes. Call a physician if irritation persists.

Inhalation:Remove the victim from the contaminated area to fresh air. Call a physician incase of respiratory symptoms.

Ingestion:Consult with a physician immediately in all cases. DO NOT induce vomiting.If victim is conscious, rinse mouth and give fresh water.In case of ingestion, sit upright, drink large quantities of water to dilute the stomach contents and seek immediate medical attention.

Danger:Hydrogen Peroxide solutions are strong oxidizers and corrosive to the eyes, mucous membranes and skin.

My comment: treat HP solutions above about 15% as carefully as your would similar concentrations of nitric acid.

The 1% concentration decay per year in normal room temp storage is of particular interest.

Also, the warning to store it with the lid not air tight is worth notice. It may be able to burst plastic containers in time, and if concentrated, could start a fire as it soaked combustibles.

They DO NOT allow concentrated HP containers to be stored on wooden pallets for that very reason. Same may go for wood floors...

Be safe and avoid being astounded. A HP fire may accellerate like a gunpowder contaminated floor, giving NO time to fight it, while small. I store gallon HP jugs in a 5 gallon plastic bucket outer containment vessel which has a non gasketed lid.

Go forth and make a joyous noise...

[rjche]

Further notes on HP

I checked a gallon of 50% stored 4 years and it was still heavy as hell meaning it has not lost much strength.

I don't have the sp gr figures, but sp gr would be a good way to judge the concentration of the stuff, and especially the concentration decrease over prolonged storage at room temp. If anybody finds sp gr versus concentration data please post it.

That will make a world of difference in conserving chemicals when making AP with unknown concentrations.

At the url (down below) you will find a very informative FAQ on hydrogen peroxide.

Of particular note to us is that it can be concentrated by freezing, up to 30% rather easily and up to 62% as the limit, WITHOUT DANGER.
Boiling is risky, see below.


This faq is very informative and a must read for AP tinkerers.

<a href="http://webhome.idirect.com/~earlcp/FAQs/FAQ.html" target="_blank">http://webhome.idirect.com/~earlcp/FAQs/FAQ.html</a>

It contains links to people who have had accidents with HP, etc.

Roughly, as you get past about 30% in concentrating it by anything but freezing, it gets dangerous for tinkerers.

Basicly when freezing lower concentrations of HP, it's the water that freezes and leaves concentrated HP as a liquid.

In boiling (not recommended for strong solutions) it's the HP that remains and the water that boils off. It can run away when the conc gets above about 50% or so (my estimate, don't bet on that) if there is any contamination at all, or if the heat added by HP decomposing causes uncontrollable (in the time available) temp rise. This can spray HP around the room or explode.

( I expect if temp was being watched when it started to ramp up there MAY be time to drown it in cold water as one does NG that turns yellow during making. Haven't got experience on runaway hot conc HP so can only give my speculations. Wisely suit up if you try it.)

IF you are going to play with HP do get the FAQ on your computer and consult it before doing anything with it. Read it at least once a year to restore your respect for it.

Remember some mistakes can happen in a tenth of a second or so. Others not so drastic can cause you to cream yourself running into stuff in an unplanned speedy exit.

Don't mix stuff with concentrated HP without consultation. Most things mixed with it go badly (dents in armor and/or scorched spots).

Making a fog of it in a room can cause lethal (delayed) lung damage before you can exit, IF YOU DON'T HOLD YOUR BREATH. Its harm is not apparent for several minutes on the skin or inhaled or ingested.

Only some mixtures with it are peaceful. Many pretend peace, but later, when you ain't looking they do their thing, like chlorate phosphorus mixtures.

Kinda like having a pet adult boa constrictor. It may grow so fond of you that one day the idea comes that "dang I like you so much I could just eat you", and in keeping with its single track mind, it promptly does.

Later it will probably form another idea "dang I miss him".
Gonna have to find me another friend. That one didn't last hardly at all.

If those, who have stories to tell how HP abused them, will post here they will be enjoyed by all.

[rjche]

Testing the concentration of HP using a battery hydrometer.
strength hydrometer reading

0% 1000
3% 1011
6% 1022
12% 1045
15% 1056
20% 1075
25% 1094
30% 1113
35% 1153
40% 1174
45% 1195
50% 1190
55% 1216
60% 1237
70% 1279
80% 1321

These data from specs on page at <a href="http://www.kencro.ca/HPSPECMSD.htm" target="_blank">http://www.kencro.ca/HPSPECMSD.htm</a>

There it gives the data for 35% and 50%.
35% 9.45 lbs per gallon, sp gr 1132 from that we get water =9.45/1.132 =8.3480 lbs/gal
50% 9.98 lbs per gallon, sp gr 1195 9.98 lbs/gal / 8.348 =1.195 sp gr.

From those two points the above sp gr readings for a battery hydrometer were interpolated. There appears to be a slight non linearity or error in the specs given in that calculating the delta between 0% and 35% has slight differnce from that calc from 0 to 50%. This would not amount to a concern with our uses of it however.

This data is valuable as to ascertaining the degree of degradation in old HP.

If you have gram scales, and no hydrometer. weigh a 100 cc container empty, add 100 cc HP, and weigh it again. Subtract the weight of the container and the resulting weight of your 100cc of HP will be 100 times the sp gr.

multiply the weight of HP by 10 to get the hydrometer reading.

divide the weight of HP by 100 to get the sp gr.

Example 100 cc beaker weighs (fictional) 100 grams
filled with 35% hp it will weigh 100 +113.2 or 213.2 grams

213.2 total - 100 glass weight = 113.2 grams liquid.

113.2 x 10 =1132 hydrometer reading

113.2 div by 100 = 1.132 sp gr of the HP

This weighing method is much more accurate than the battery hydrometer, but either are good enough to make AP, by ratio to known accurate formula ratios of acetone and acid. As I understand it the concentration of the acid only relates to the speed of formation of product, within wide variations. highly conc acid (sulfuric) needs be cut to battery acid strength. Most places that sell lead acid batteries (car batteries etc) sell very pure sulfuric acid used to fill dry charged batteries or to renew spilled acid. It's of the proper strength to use for AP, which is around 30% concentration. HCL only comes in about 30% commercially.

HP would apparently have to be several years old to show significant degradation if it looses 1% per year as given by one mfgr of 35% and 50% HP.