It is a colourless liquid with a slightly irritating, fruity odour.

It is a colorless liquid with a penetrating, irritating odor.

A sharper, irritating odor, like the back of a garbage truck.

Ethenone is a colourless gas at STP and has a sharp irritating odour.

It is a colourless, fuming liquid with an irritating odour.

A gas at room temperature, formaldehyde is colorless and has a characteristic pungent, irritating odor.

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

It is a clear colorless liquid with a sharp, irritating odor.

Like all chemical substances ammonia can be toxic, but it is also has a very irritating, characteristic odor.

He identified the pungent, irritating odor of formaldehyde.