In a pure state, it forms bright-yellow crystals with a characteristic irritating odor, resembling that of chlorine, bleach, and hot plastic or formaldehyde.

[7] Another major process involves the direct hydroxylation of phenol by acidic hydrogen peroxide:

[11] When heated to near its melting point, 1,4-benzoquinone sublimes, even at atmospheric pressure, allowing for an effective purification.

Impure samples are often dark-colored due to the presence of quinhydrone, a dark green 1:1 charge-transfer complex of quinone with hydroquinone.

[8] Benzoquinonium is a skeletal muscle relaxant, ganglion blocking agent that is made from benzoquinone.

An application is found in this step of the total synthesis of Metachromin A:[21] Benzoquinone is also used to suppress double-bond migration during olefin metathesis reactions.

[25] The compound can interfere with cellular respiration, and kidney damage has been found in animals receiving severe exposure.

Its ability to sublime at commonly encountered temperatures allows for a greater airborne exposure risk than might be expected for a room-temperature solid.

IARC has found insufficient evidence to comment on the compound's carcinogenicity, but has noted that it can easily pass into the bloodstream and that it showed activity in depressing bone marrow production in mice and can inhibit protease enzymes involved in cellular apoptosis.