Guidance

Picric acid: general information

Updated 5 February 2025

Overview

Picric acid is a colourless to yellow crystalline solid with a bitter taste. It is highly explosive when dry. Other names for picric acid are carbazotic acid, picronitric acid and TNP.

Uses of picric acid

Picric acid is used in laboratories as a chemical reagent. It has been used as an explosive and in the production of batteries. It has also been used in the leather and textile industry and in the production of coloured glass and dyes. In the 20th century it was used as an antiseptic in medical ointments to treat wounds including burns.

How picric acid gets into the environment

Picric acid may enter the environment during its production and use.

Exposure to picric acid

Exposure to picric acid is most likely to occur in an occupational setting via breathing in picric acid dust or fumes and via skin contact. However, safe limits are enforced to protect the employees; such levels are below those that are thought to cause harmful effects.

The general public is unlikely to be exposed picric acid at concentrations that cause adverse health effects.

How exposure to picric acid can affect your health

The presence of picric acid in the environment does not always lead to exposure. In order for it to cause any adverse health effects you must come into contact with it. You may be exposed to picric acid by breathing or eating it or by skin contact with it. Following exposure to any chemical, the adverse health effects you may encounter depend on several factors, including the amount to which you are exposed (dose), the way you are exposed, the duration of exposure, the form of the chemical and if you were exposed to any other chemicals.

Breathing in picric acid dust or fumes can cause sore throat and lung irritation. Ingestion may cause severe stomach upset and ulcers. Picric acid can also be absorbed into the body following inhalation or ingestion causing dizziness, headache, and weakness. In severe cases fitting and coma can occur. Exposure to high concentrations can result in yellow staining of the skin and hair and in some cases yellow tinted vision.

Skin contact with picric acid can cause irritation and yellow staining of the skin. Contact with eyes may result in irritation and damage to the eye.

Picric acid and cancer

There is no data on whether picric acid causes cancer in humans.

Pregnancy and the unborn child

Due to lack of data it is not possible to assess the reproductive and developmental effects of picric acid. It is unlikely that exposure to low concentrations of picric acid which do not affect the mother would result in harm to the unborn child.

Children

Children exposed to picric acid are expected to show same symptoms as exposed adults.

What to do if you are exposed to picric acid

It is very unlikely that the general population will be exposed to a level of picric acid high enough to cause adverse health effects. However, if you have any health concerns regarding exposure to picric acid seek guidance from your GP or contact NHS 111.

Additional sources of information

UKTIS. Best Use of Medicines in Pregnancy

The information contained in this document from the UKHSA Radiation, Chemicals and Environment Directorate is correct at the time of its publication.

Email chemcompendium@ukhsa.gov.uk if you have any questions about this guidance or enquiries@ukhsa.gov.uk if you have any other questions.

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