How dangerous is picric acid?
Question. Older colleagues tell of picric acid exploding with great violence, but always in other labs. Is there really a risk of explosion? Answer. From the late 19th Century until the First World War, picric acid was used as a high explosive in military shells. Its melting point (122C) is quite well separated from its exploding temperature (above 300C). Picric acid can be ignited by a nearby spark at temperatures above its flash point of 150C. More sensitive explosives can be formed by chemical reaction of picric acid with other substances. An example is ammonium picrate (which has been used in histology to fix vital stainings with methylene blue). In 1915 a French freighter, the Mont Blanc, full of expired explosives, caught fire in the harbour of Halifax, Nova Scotia. The largest man-made, non-nuclear explosion followed, and it’s customary to blame it on picric acid, which probably accounted for much of the cargo. When you buy a bottle of picric acid for the lab, the yellow powder
Question. Older colleagues tell of picric acid exploding with great violence, but always in other labs. Is there really a risk of explosion? Answer. From the late 19th Century until the First World War, picric acid was used as a high explosive in military shells. Its melting point (122C) is quite well separated from its exploding temperature (above 300C). Picric acid can be ignited by a nearby spark at temperatures above its flash point of 150C. More sensitive explosives can be formed by chemical reaction of picric acid with other substances. An example is ammonium picrate (which has been used in histology to fix vital stainings with methylene blue). In 1915 a French freighter, the Mont Blanc, full of expired explosives, caught fire in the harbour of Halifax, Nova Scotia. The largest man-made, non-nuclear explosion followed, and it’s customary to blame it on picric acid, which probably accounted for much of the cargo. When you buy a bottle of picric acid for the lab, the yellow powder
