Home Podcasts THMG118 – Functional Group – Organic Peroxides

THMG118 – Functional Group – Organic Peroxides


In this episode we talk about the functional group Organic Peroxides. There some explosive information in here! (bad joke)

Thanks for listening and watching!

what are they
they are a function group. A very very very auwnery functional group
technically they are any organic compound having two oxygen atoms that are bonded together. Not in the double bond that we see in compounds like O2 but in a single bond o-o.
This 0-0 bond are really not how oxygen wants to be. it makes it unstable and that instability.
so what distinguishes peroxides from organic peroxides.
Ok well a peroxide has the the two oxygens attached to each other in a single bond. Buy oxygen really want to bond twice. So its combines with other stuff.
As a general rule of thumb these carbon based things we tend to look at as flammable, or at the very least a fuel.
right non- carbon based things generally tend to not be “fuels”
That’s not saying they can’t burn and that they can cause problems. Believe me peroxides are still really bad ass.
organic peroxides are just that much more worse because they have a fuel right next to the oxygen.
So when they start to decompose they can instantly react with the available oxygen.
Yes and what makes them even more bad ass is that they start to break down at really low temps.
not like cryo low but some can break down in the negative degrees.
This is going to be a really important concept when responding to peroxides but well chat more about that later
ok follow me with this a moment
if i am looking to Make a product, what do i start out with.
raw materials.
how to do do from a raw material to a finished product.
you have to change it. and most of the time that change means a chemical reaction of some type.
and because of their instability and desire to react they are great at helping to make those changes in industry.
They are used as accelerators in chemical reactors, activators, and catalysts
when trying to combine large compounds, organic peroxides are great at cross-linking
They are like a host introducing people at a party that haven’t met, but will get along together, maybe Curing agents, hardeners, initiators and promoters are also in the repertoire of actions that OP can do.
As a results we can find peroxides in almost any industry and any factor.
in fact if your responding in to a factory, especially a chemical factory you would be better off assuming they have an organic peroxide somewhere on the grounds than not.
how are they transported
Rail cars. Class DOT 103, 104, 105, 109, 111, 112, 114, 115, or 120
Cargo tanks. Specification MC 307, MC 310, MC 311, MC 312, DOT 407, and DOT 412 cargo tank motor vehicles with a tank design pressure of at least 172 kPa (25 psig) are authorized.
Portable tanks.
DOT 51, 57, IM 101 portable tanks
these tanks and numbers correspond to types of tank that the dot has specifications on. So example the 51 is a steel tank. and under that specification it has to meet certain requirements. This isn’t a show on DOT but it was just to illustrate the types of tanks as examples.
The portable tank must be designed for a test pressure of at least 0.4 MPa (4 bar).
portable tank must be fitted with temperature-sensing devices.
The portable tank must be fitted with pressure relief devices and emergency-relief devices. Vacuum-relief devices may also be used.
Pressure relief devices must operate at pressures determined according to both the properties of the hazardous material and the construction characteristics of the portable tank.
Fusible elements are not allowed in the shell.
They can also be found in Drums: Jerrica Boxes: and Composite packagings with a plastic inner receptacle:
so really they come in all different shapes and size containers.
Let Bob go through the GHS and labeling
The Globally Harmonized System (GHS) of classification and labeling of chemicals has seven categories for organic peroxides, which are described below.
Type A – An organic peroxide as packaged that can detonate or deflagrate rapidly;
Type B – An organic peroxide as packaged that does not detonate or deflagrate rapidly but is capable of undergoing a thermal explosion;
Type C – An organic peroxide as packaged that possesses explosive properties but will not detonate, deflagrate or thermally explode; and
Types D through F – Organic peroxides that have shown hazards such as partial detonation, etc., when tested in a laboratory but do not possess these hazards as packaged.
how are they stored
Most organic peroxides are going to be stored in some kind of chilling unit.
a rule of thumb is that most peroxides are going to be kept a temperature that is about 20 degrees below the SADT
We should probably go into SADT a little. it stands for Self accelerating decomposition temperature is the lowest temperature at which self accelerating decomposition may occur with a substance
This is going to be one of the critical pieces of information we need to establish with almost any peroxide incident.
So what exactly does that mean. ok we said that organic peroxides are unstable and break apart easily. Well with so many chemical that are unstable, temperature places a role in this.
as temperature increase so does the rate at witch that O.P. will break down. Unfortunately the break down reaction is very exothermic. So it give off heat in the process.
That heat then breaks down the surrounding OP and starts a chain reaction that there is no getting back from if the temp is two high.
And since in an organic peroxide my oxygen is mixed with my fuel i have the potential for a reaction to happen so fast that it can deflagrate or even detonate.
Some shock waves off a detonation of OP can get up to 9000 m/s. And the better or stronger the container is the higher the pressure builds up and lead to a bigger or faster reaction.
That a bad day.
This really becomes and issue during transportation incidents where the ability to chill the OP is reduces or eliminates,
or the time it takes to get from point a to b is underestimated or delayed.
or the transpiration vessel is involved in a fire.
As we approach one of these vessel we really need to try to obtain a temperature of the product and a pressure reading inside the vessel if the vessel has a pressure gauge.
comparing that information to the SADT can really help us to determine the next step.
what kind of information should i be looking for on specific chemical?
SADT- Self accelerating decomposition temperature is the lowest temperature at which self accelerating decomposition may occur with a substance in the packaging as used in transport.
how do i find that info.
cameo examples.
TERT-AMYL PEROXY-2 ETHYLHEXANOATE gave very little info on the chemical. It gave some basics and a lot of the stuff it gave was copy and pasted out of the erg.
in fact they didn’t list a single chemical physical property
They did tell us Colorless to pale yellow liquid. May explode if exposed to heat , shock, or friction. Material must be stored and transported in temperature controlled container.
and Insoluble in water.
and when we looked in the niosh there was nothing
PUBCHEM had some more information but honestly nothing that would help with this chemical
Chemicalbook gave me some reactivity infor that says “explodes with great violence when rapidly heated to a critical temperature; pure form is shock sensitive and detonable”
ok but nothing is giving us what we really need.
so now we switch to my (mike’s) favorite way of looking up chemicals and that is threw and sds. So we did just that. SDS this big chemicals
we got some info on fire suppression, “Extinguish a small fire with powder or carbon dioxide then apply water to prevent reignition. Cool closed container with water.
We also got some clean up info to use inert absorbent like vermiculite for disposal. and to keep the contents moist. never confine the waste.
AHAH finally as we come downthe sheet we find what i have been looking for. avoid temps below -20. For safety store below 20 degrees c which for us using the barbaric system of measurements is about 68 Degrees F.
This would make sense that tap water would help keep it below its temp and not above.
actually that’s a really good point. this specific chemical says to use water. Because a safe temp is 68 F. Another chemical might not be so happy at that temp and using water to cool the container may make things worse
All the more reason that when dealing with organic peroxides to remember that each chemical is its own animal.
Further down the sheet we actually get to one of the most important pieces of info for an organic peroxide. The SADT
Otherwise known as the self accelerating decomposition temperatures.
For this chemical. NOT all Organic peroxides, for this chemical it is 35C or 95F. So know i have some great information to be able to know how close I am to complete destruction.
This why I really do try to go to my SDS sheets first.

The Hazmat Guys

Author: The Hazmat Guys


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