[8] In 1871 Hermann Sprengel proved it could be detonated[9] and afterwards most military powers used picric acid as their main high explosive material.

Picric acid was the first strongly explosive nitrated organic compound widely considered suitable to withstand the shock of firing in conventional artillery.

Nitroglycerine and nitrocellulose (guncotton) were available earlier, but shock sensitivity sometimes caused detonation in an artillery barrel at the time of firing.

In 1885, based on research of Hermann Sprengel, French chemist Eugène Turpin patented the use of pressed and cast picric acid in blasting charges and artillery shells.

Laclede Gas reports being asked to expand production of phenol (and toluene) to assist the war effort.

He responded by undertaking production of phenol at his Silver Lake, New Jersey, facility using processes developed by his chemists.

He built two plants to produce the raw material benzene at Johnstown, Pennsylvania, and Bessemer, Alabama, replacing supplies previously from Germany.

Dunnite is more powerful but less stable than the more common explosive TNT (which is produced in a similar process to picric acid but with toluene as the feedstock).

In metallurgy, a 4% picric acid in ethanol etch, termed "picral", has been commonly used in optical metallography to reveal prior austenite grain boundaries in ferritic steels.

When glucose, picric acid and sodium carbonate are combined and heated, a characteristic red color forms.

[citation needed] It reacts with proteins in the skin to give a dark brown color that may last as long as a month.

[citation needed] During the early 20th century, picric acid was stocked in pharmacies as an antiseptic and as a treatment for burns, malaria, herpes, and smallpox.

Picric acid was used as a treatment for trench foot suffered by soldiers stationed on the Western Front during World War I.

[32] Picric acid has been used for many years by fly tyers to dye mole skins and feathers a dark olive green for use as fishing lures.

[citation needed] Modern safety precautions recommend storing picric acid wet, to minimize the danger of explosion.

Dry picric acid is relatively sensitive to shock and friction, so laboratories that use it store it in bottles under a layer of water, rendering it safe.

[33] Picric acid gauze, if found in antique first aid kits, presents a safety hazard because picric acid of that vintage (60–90 years old) will have become crystallized and unstable,[34] and may have formed metal picrates from long storage in a metal first aid case.

[35][36] In the United States there was an effort to remove dried picric acid containers from high school laboratories during the 1980s.