40 � Division of Chemical Hea

Elsevier Inc. All rights reserv

Ask Alice H. . .

D ear Alice H. – During a routinelaboratory clean-up day, one of ourtechnicians came across two small

(about 25 ml) containers of picric acid. Theglass bottles with plastic caps had obviouslystained yellow labels that make it difficult todetermine if the original condition of the mate-rial was liquid or solid. There is no obvious‘‘fur’’ around the edges. We are getting con-flicting recommendations as to how to handlethe material. We know there is cause for con-cern but don’t know exactly how we need tohandle the material.

Don’t want to have a blast.

Dear Don’t want to have a blast –The material 2-hydroxy-1,3,5-trinitrobenzene

(CAS No. 88-89-1) commonly referred to aspicric acid or picronitric acid or carbazotic acidis an odorless, colorless to pale yellow materialwith an intensely bitter taste. (Hence, the namepicric from the Greek word pikros, the word forbitter.) The compound is moderately toxic andmutagenic. It can be readily absorbed throughthe respiratory and intestinal tracts. TheNational Institutes of Health recommends thatlaboratory operations be conducted in a fumehood, glove box or ventilated cabinet.

There are two excellent fact sheets on picricacid hazards. One from the National Institutesof Health (NIH) and can be found at http://dohs.ors.od.nih.gov/pdf/Picric%20Acid%20REVISED.pdf. This NIH fact sheet includes aset of Operational Procedures that can be imple-mented in the laboratory.

The other authored by Mark Cameron, CIHwhich can be found numerous places on theinternet (http://www.cci.ca.gov/Reference/PICRIC.pdf). This fact sheet is written in ‘‘plainEnglish’’ with excellent references.

lth and Safety of the American Chemical Society

ed.

The issue, as you have discovered, is the‘‘common knowledge’’ and ‘‘concern’’ thathas resulted from media attention associatedwith the ‘‘local bomb disposal team’’ removingpicric acid from someone’s garage or the highschool chemistry laboratory. Yes, picric aciddoes have an ‘‘explosive’’ side as it was used inLyddite an explosive material used in bombsand grenades during World War I. (MarkCameron)

It is the dehydrated or anhydrous form ofpicric acid that is cause for concern. The NIHand Material Safety Data Sheets recommendthat if you find ‘‘large’’ quantities of picric acidthat it should be disposed of only by explosiveexperts. The NIH also references the NationalResearch Council’s Prudent Practices in theLaboratories. (A special note – Prudent Prac-tices is currently in the process of beingupdated and a new version should be availablesoon.) The North American EmergencyResponse Guidebook indicates that the driedpicric acid should be treated as an explosive.However, for smaller amounts where there isno apparent formation of crystals outside onthe container (HOWEVER, SOME CRYS-TALS MAY BE ON THREADS – which maybe enough to detonate the container), the con-tainer may be safe enough to place in a pail ofwater. (See the procedure outlined in MarkCameron’s fact sheet and the references heprovides.)

The key is to understand how much materialthat is present, the physical state of the mate-rial, and the local capabilities of those who willbe handling the material. If in doubt, contactyour local experts, safety department, safetyconsultants, or other technically qualified indi-viduals.

1871-5532/$36.00

doi:10.1016/j.jchas.2009.05.003