[sharbeldam]

1) Why does it say that H2O2 3% Or even 17.5% need to be stored in room temperature but a 35% needs to be stored in 10C?
2) is it ok to put it in the fridge (3-4C) even though it says that 35% needs to be stored in 10C?

one more thing please, it says ofcourse that inhalation of it is harmful, but what exactly does that mean? is it safe to work with it outside without a face mask? because it doesnt vaporize in cool temperatures does it?

Thanks in advance

[AWK]

Concerning the first part - rather nonsense
http://www.h2o2.com/technical-library/default.aspx?pid=66&name=Safety-amp-Handling
http://www.h2o2.com/technical-library/physical-chemical-properties/physical-properties/default.aspx?pid=22&name=Boiling-Points-and-Freezing-Points
Check in details www.h2o2.com.
Concerning  the second part
Hydrogen peroxide is a mutagen. Inhaled causes pulmonary edema.

[sharbeldam]

So the fact that it says 10C on the bottle is wrong?
and about inhaling, i got that, but you dont actually inhale it by working with it in 19-23C outside since it doesnt vaporize at this temp... right?

[AWK]

Something needs to be written. Reasonably and safely.

[rolnor]

The safety concerns is if you expose under long time with the material, the vapor-pressure is not high at roomtemp.

[AWK]

Not everyone reads the detailed texts, so I will quote a few sentences from www.h2o2.com.
"Under normal conditions, hydrogen peroxide is extremely stable when properly stored. The dose loss in large containers, such as tanks, is less than 1% per year at normal ambient temperatures; in small containers, such as drums, the loss rate is less than 2 % per year ".

Note - smaller container - faster decomposition.

This is an important point about your question:
"Decreasing temperatures have little effect on hydrogen peroxide until they drop substantially below 0 degrees C. Crystals do not begin to appear in 35% and 50% solutions until -33C (-27.4F) and -52.2C (-62F), respectively. "

So the lower the temperature (but above -33C), the better.
But storing reagents at such low temperatures is cumbersome and expensive and only used when absolutely necessary.

It is true that the vapor pressure at lower temperatures is lower. In the case of toxic substances in accordance with their toxicity classifications, each country has its own regulations and must be followed (sometimes even individual laboratories have their own separate regulations).
Small damage to the mucous membranes caused by hydrogen peroxide can be repaired by the body.
But when the mutagenic effect of this compound will reveal - it is not known. Maybe never.

[Enthalpy]

Just in case someone has to handle >70% concentration some day, peroxide behaves differently then, as the decomposition heat suffices to evaporate the liquid.
http://w.hydrogen-peroxide.us/chemical-handling-toxicity/AIAA-2004-4146_Field_Handling_of_hydrogen_peroxide.pdf
Ignites organics by contact including clothes and skin, detonates without fuel, decomposes slowly then explosively, and other petty jokes.

[sharbeldam]

Thank you all