btw I have about 350 kg to dispose of.
I would consider treating it with acid. That is the commercial process for the production of phenol and acetone. I don't know the particulars of that reaction, how exothermic, etc. Since you have such a large amount, I would become tired of running 3,500 x 100 g batches in any process. A 350 kg x 1 batch could create so much heat that could not be controlled because of the limited amount of surface area so it too could be dangerous. If you have 350 kg, could you sell it to someone interested in the peroxide or to someone basic in the phenol-acetone process?
Crap, if you do the treatment in a large enough vessel, say 1000-1600L you will have no problem with heat exchange if you are in a proper pilot plant anyway the reaction will be addition controlled, so heat removal should be no problem. You place 10-20% aqueous solution of sodium sulfite in the reactor, cool to 10°C, add dropwise keeping the temp between 10°C and 20°C a solution of the hydroperoxide in toluene, stir well.
You can also do it at the reflux temperature of the solvent mixture, reflux cooling, providing you control your solvent loss by evapoartion.
I am a development chemist so I am aware of these things. What is essential is to to all the thermal analysis (DSC etc) before you start so you know what to expect.
I've done things like this on a much larger scale then 350kg, just know your system before you start