Discovery of potentially explosive picric acid in a number of museum collections has highlighted the need for museums to have their collections checked for this hazardous substance.
The Napier Library and MTG building closed after picric acid was found in a routine check of a historical medicine cabinet so the substance could be safely removed and destroyed by authorities.
Waikawa Museum also took immediate action to close when a tin of picric acid 246 was discovered. The substance was on display as part of a first aid kit from the 1900s.
Picric acid is a yellow, toxic substance. It is classified as a flammable solid when wetted with more than 30% water, and is highly explosive when water content is below 30%. Dry picric acid is sensitive to heat, shock and friction. As it ages the acid becomes a flammable solid or a highly explosive powder and needs expert handling.
Picric acid has been used as a yellow dye, explosive agent, an antiseptic and treatment for burns, skin injuries, herpes, smallpox and even trench foot during World War II. The substance appears to stop being in common usage in medical and first kits after the 1960s.
Picric acid soaked gauze or lint was often packaged in first aid kits or was available as a bottled liquid. Dyes, medical kits and solutions containing the acid may be present in other museum collections.
If you find old medical or first aid kits that list picric acid pads in their contents, or bottles of picric acid or yellow dyes in your collection, in the first instance leave them in place and contact your local police or Fire and Emergency services who will be able to assist.
If disposal is required the police or fire service will contact New Zealand Defence Force Explosive Ordnance Disposal (EOD) on your behalf. EOD are available at all times to carry out safe disposal of any explosive substances.
Further Hazardous Materials resources
Find out more about Hazardous collection items and minimising risk in NSTP He Rauemi Resource Guide 35: Museum Security
The Hazardous materials in museum collections factsheet from Museums and Galleries of NSW lists the sorts of materials in general museum collections that may present a danger, either to museum workers and visitors, or to other objects in the collection.