Reported in EPA TSCA Inventory.

Quinhydrone(106-34-3) also can be called 2,5-Cyclohexadiene-1,4-dione compd with 1,4-benzenediol (1:1) and 1,4-Benzoquinone - 1,4-benzenediol (1:1). It is hazardous,so the first aid measures and others should be known.Such as: When on the skin: first,should  flush skin with plenty of water immediatelyfor at least 15 minutes while removing contaminated clothing. In addition, Quinhydrone is moisture sensitive with air and light, and can be stable under normal temperature and pressure conditions. It is not compatible with strong oxidizing agents, and you must not take it with light, exposure to air, excess heat and incompatible materials. And also prevent it to broken down into hazardous decomposition products: carbon dioxide, carbon monoxide.

Physical properties about Quinhydrone are: (1)ACD/LogP: 0.644; (2)ACD/LogD (pH 5.5): 0.64; (3)ACD/LogD (pH 7.4): 0.64; (4)ACD/BCF (pH 5.5):1.82; (5)ACD/BCF (pH 7.4): 1.82; (6)ACD/KOC (pH 5.5): 53.40; (7)ACD/KOC (pH 7.4): 53.33; (8)#H bond acceptors: 2; (9)#H bond donors: 2; (10)#Freely Rotating Bonds: 2; (11)Flash Point: 141.6 °C; (12)Enthalpy of Vaporization: 54.61 kJ/mol; (13)Boiling Point: 286 °C at 760 mmHg; (14)Vapour Pressure: 0.00157 mmHg at 25°C

When you are using this chemical, please be cautious about it as the following:
1. In case of contact with eyes, rinse immediately with plenty of water and seek medical advice;
2. Wear suitable protective clothing;
3. Avoid release to the environment. Refer to special instructions safety data sheet;
4. Wear suitable protective clothing and eye/face protection;
5. Do not empty into drains;

You can still convert the following datas into molecular structure:
(1)InChI=1S/C6H6O2.C6H4O2/c2*7-5-1-2-6(8)4-3-5/h1-4,7-8H;1-4H;
(2)InChIKey=BDJXVNRFAQSMAA-UHFFFAOYSA-N;
(3)Smilesc1(ccc(O)cc1)O.C1(C=CC(=O)C=C1)=O

The toxicity data is as follows: