ARS | Publication request: A NEW METHOD FOR ESTIMATING THE PERMEABILITY OF PLASTIC FILMS TO FUMIGANT VAPORS

Submitted to: Proceedings of International Research Conference on Methyl Bromide Alternatives
Publication Type: Abstract
Publication Acceptance Date: November 4, 1999
Publication Date: November 4, 1999
Citation: Papiernik, S.K., Yates, S.R. 1999. A new method for estimating the permeability of plastic films to fumigant vapors. Proceedings of International Research Conference on Methyl Bromide Alternatives. San Diego, CA. Nov. 1-4, 1999. Paper No. 30. pp. 30-1 to 30-3.

Technical Abstract: When greenhouse and field soils are fumigated, the soil surface is often covered with a plastic tarp to reduce loss of the chemical via volatilization. Plastic films that have reduced permeability to soil fumigants, particularly MeBr, have been developed in response to the call for management practices that reduce emissions and maintain or increase the efficacy of soil fumigants. To assist in the development of these management practices, a rapid, accurate method to measure the permeability of plastic films to soil fumigants is needed. This paper describes a new method for estimating the mass transfer coefficient of gases diffusing through plastic films. Unlike currently-used methods, which use a flow-through chamber under steady state conditions, the transfer of fumigant across a film was determined in a static chamber. This method was used to measure the permeability of HDPE to MeBr, 1,3-dichloropropene (1,3-D), and chloropicrin. Results indicated that 1-mil HDPE is permeable to fumigant compounds, with 1,3-D having the highest mass transfer coefficient and MeBr the lowest of the fumigants tested. This approach holds promise for use as a relatively rapid and reliable method to determine the permeability of plastic films to fumigant compounds. This method, which requires a minimum of equipment, is especially useful as a screening tool in the development of new agricultural films or soil fumigants.