Well that's laughably wrong.
First, most electronics are already treated hazardous waste because they often contain lead, mercury, cadmium and other toxic materials. Adding a spec of gallium arsenide sealed in a plasticf IC package that will outlast the human race is not going to make any of it more hazardous.
Second, LEDs. Red, yellow, orange and infrared LEDs use gallium arsenide. Seen any hazmat warning stickers on your TV remote lately? Of course not.
Having gallium arsenide in a chip does cause it to be classed as being any more hazardous than any other electronic device.