May Letter to the Editor

I would like to clarify some misleading statements made in an article in the April issue of Safety+Health magazine. The title of the article was OSHA issues health bulletin on grain-industry fumigants.

The article was based on an OSHA Safety and Health Information Bulletin released in January, and your article correctly presents what was stated in the SHIB. I have spoken to OSHA by phone and followed up with a letter that will hopefully correct the misleading statements in future document(s).

I am writing to clarify these misleading statements for your readers.One of the 25 fumigants covered by the SHIB was phosphine. Phosphine is grouped in the same paragraph with other fumigants that the SHIB states cause human health effects, including “…permanent central nervous system damage, heart and vascular disease and lung edema as well as cancer.”

None of these effects apply to phosphine.

Thus far, human health and laboratory animal effects from phosphine exposure are all reversible except for death, which has occurred in humans when used improperly and in gross violation of the label. Please refer to a peer-reviewed scientific publication that reviewed all of the pertinent toxicology literature until its date of publication:

Pepelko B, Seckar J, Harp PR, Kim JH, Gray D, Anderson EL. (2004) Worker Exposure Standard for Phosphine Gas. Risk Analysis 24(5):1201-1213.

The Environmental Protection Agency has the responsibility to ensure phosphine and phosphine-producing agents are used safely. Phosphine is a fairly toxic restricted-use pesticide. EPA and registrants have therefore established labels for these products that are protective to workers. An 8-hour Time Weighted Average (TWA) and a Short Term Exposure Limit (STEL) have been established, and every fumigation is required to have a written fumigation management plan to ensure workers are protected. When applied according to the label, phosphine has and will continue to be used quite safely.

Joel A. Seckar, Ph.D., D.A.B.T. (Emeritus)
Seckar Toxicology Consulting LLC
Dumfries, VA