1.1 This test method covers the measurement of the transmission of a gas through plastic membranes, sheeting, films, and fabric materials using a static sealed diffusion chamber. The test method monitors gas diffusion across a film membrane and provides measurements of (1) gas concentrations on each side of the film membrane and (2) estimates of the mass transfer coefficient (MTC) for the tested gas and film material. The MTC represents the film permeability and is independent of the concentration gradient used during testing, which simplifies some aspects of the experimental design. 1.2 This test method permits the loading of mixed vapors and simultaneous determination of the permeability of one film to various gases. 1.3 Units-The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
U.S. EPA is requiring a suite of complementary mitigation measures to protect people and the environment from risks of the soil fumigant pesticides. Among the requirements, use of high-barrier plastic tarps by individuals and organizations during the fumigation of soils and structures to control the emission of fumigants is the primary tool. The permeability of the films to fumigants varies widely with material type, manufacturing techniques, and manufacturer. In addition, many factors such as field conditions, temperature, fumigant type, film stretching, and gluing in the field, could potentially affect the permeability of the films. Currently, there is no standard method to reliably determine the permeability of agricultural films to various fumigant pesticides. Film manufacturers, growers, fumigant applicators, and regulators all are asking for a standard method to determine the permeability of the plastic films to fumigants to reliably and accurately control the risks asociated with fumigation.
Keywordsfumigants; mass transfer coefficient; MTC; plastic film permeability
The title and scope are in draft form and are under development within this ASTM Committee.Back to Top
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