Anugrah Shaw

Comparison of gravimetric and gas chromatographic methods for assessing performance of textile materials against liquid pesticide penetration.

Penetration of liquid pesticides through textile materials is a criterion for determining the performance ofprotective clothing used by pesticide handlers. The pipette method is frequently used to apply liquid pesticides onto textile materials to measure penetration. Typically, analytical techniques such as gas chromatography (GC) are used to measure percentage penetration. These techniques are labor intensive and costly. A simpler gravimetric method was developed, and tests were conducted to compare the gravimetric and GC methods of analysis. Three types of pesticide formulations and 4 fabrics were used for the study. Diluted pesticide formulations were pipetted onto the test specimens and percentage penetration was measured using the 2 methods. For homogeneous formulation, the results of the 2 methods were fairly comparable. However, due to the filtering action of the textile materials, there were differences in the percentage penetration between the 2 methods for formulations that were not homogeneous.

Effect of exposure time on the sorption of pesticide emulsifiable concentrates through microporous fabrics

applications and handlers has been a topic of concern for over two decades. Research conducted by Maibach (1971) indicates that dermal sorption could account for up to 87% of the total sorption by the human body. AI though researcher s have proved that use of protective clotbing can reduce dermal exposure, there is stil 1 a need for clothing that provides comfort, protection, and can be satisfactorily laundered (Langhlin 1986). Most previous studies conducted on Goretex fabrics used fiel d strength pesticide solutions or emulsions (Branson et al. 1986, Easter 1983, Orlando et al. 1981) and some suggest that the above fabric type could provide adequate protection against a limited number of pesticides.

Protective clothing for pesticide operators: part I – selection of a reference test chemical for penetration testing

A systematic approach was taken to develop a database for protective clothing for pesticide operators; results are reported as a two-part series. Part I describes the research studies that led to identification of a pesticide formulation that could serve as a reference test chemical for further testing. Measurement of pesticide penetration was conducted using different types of pesticide formulations. Six fabrics were tested using 10 formulations at different concentrations. Three formulations were subsequently selected for further testing. Analysis of the data indicated that, when compared with other formulations, mean percent penetration of 5% Prowl 3.3 EC [emulsifiable concentrate diluted to 5% active ingredient (pendimethalin)] is either similar to or higher than most test chemicals. Those results led to choosing 5% Prowl 3.3 EC as a reference test liquid. Part II of the study, published as a separate paper, includes data on a wide range of textile materials.

Development of a new test cell to measure cumulative permeation of water-insoluble pesticides with low vapor pressure through protective clothing and glove materials

A collaborative approach, involving resources and expertise from several countries, was used to develop a test cell to measure cumulative permeation by a solid-state collection technique. The new technique was developed to measure the permeation of pesticide active ingredients and other chemicals with low vapor pressure that would otherwise be difficult to test via standard techniques. The development process is described and the results from the final chosen test method are reported. Inter-laboratory studies were conducted to further refine the new method and determine repeatability and reliability. The revised test method has been approved as a new ISO/EN standard to measure permeation of chemicals with low vapor pressure and/or solubility in water.

Protective clothing for pesticide operators: part II – data analysis of fabric characteristics

Development of objective measurements is an important requirement for establishing performance-based standards for protective clothing used while handling pesticide. This study, the second in a two-part series, reports on the work completed to evaluate the performance of approximately 100 fabrics that are either used or have the potential to be used for garments worn by operators while applying pesticides. Part I, published separately, provides an overview of these issues and describes research undertaken to select a test chemical for use in subsequent studies. The goals of this study were first to develop a comprehensive approach to evaluate the performance of garments currently being used by pesticide operators, and second, to use the laboratory and field data in the development of performance specifications.

Protective clothing for pesticide: Development of a database to validate ISO 27065 test chemical

An ISO performance standard dedicated to protective clothing for operators handling plant protection products was published in 2011. The standard requires measuring penetration through fabrics with a test chemical representative of plant protection product with the highest penetration. In Europe, the EC Regulation No 1107/2009 requires data to substantiate that the protective clothing specified on plant protection product label provides adequate protection against that product. This can be done by testing with the specific product or through extrapolation. A study was conducted to develop a database to better understand the penetration behavior of plant protection products through protective clothing compared to the reference test chemical for ISO 27065. The aim of the study was to determine whether testing with the reference test chemical for ISO 27065 is sufficient to serve as the basis for extrapolations. The study was also used to select a product to be used as the basis for the development of a surrogate, as the current ISO 27065 test chemical is planned to be changed. A fabric that met ISO 27065 Level C1 requirements was tested with ISO 27065 test chemical as well as 65 commercial plant protection products that represent a wide range of formulation types. A sub-set of 12 plant protection products was selected for further testing with two additional Level C1 fabrics. Based on the statistical analysis, formulation types, for which there is data in the database, could be used for extrapolation purposes. In addition, a reference product was selected as the basis for the development of a non-commercial surrogate test chemical.