An umbrella term, the word ‘agricultural chemicals’ encompasses a diverse range of substances that are available in many concentrations and forms including liquids, powders, granules, and pellets. Some aim to improve or control growing conditions and processes (soil desiccants and harvest aids), whereas others are designed to kill or minimize crop or livestock threats including animal pests, weeds, and insects. These are defined in the following broad groups, including some common examples of each:
Pesticides pyrethroids, sodium fluoroacetate, zinc phosphide and strychnine;
Herbicides glyphosate, paraquat and diquat;
Insecticides organophosphates and neonicotinoids;
Fungicides calcium polysulfide, captafol and captan and;
Fumigants methyl bromide
Exposure to these chemicals can occur in many ways. Obvious scenarios include treatment of animals, crops, plants, and grain stores in agricultural or livestock production settings, but other known risk environments include forestry, gardening, professional (or domestic) pest control, or exposure through the spraying of public parks, pavements, and playgrounds. Any process that employs fumigation for parasite management, such as cross-border biosecurity, also leaves workers open to exposure.
Why ‘no exposure’ is impossible – Protect yourself with PPE
As with many workplace safety hazards, complete elimination is an unachievable goal, so a program of harm minimization based on rigorous assessment must be implemented. When conducting a workplace hazard assessment, it’s important to consider scenarios where multiple substances are found, as the effect of an individual chemical can be enhanced or significantly changed when combined with another.Utilizing appropriate personal protective equipment (PPE) is the best defence against workplace agricultural chemicals exposure hazards.
PPE options in these applications can include gloves, clothing, boots, cuffs, face shields, aprons and eye protection including goggles and glasses. Adequate chemical protection calls for a detailed understanding of the substances to which workers are exposed. Protective clothing and gloves are manufactured in a wide range of styles and materials which mean they are more-or less-suited to specific applications. For example, some material types will be susceptible to failure by degradation or to permeation of certain chemical types, particularly when combined with other environmental factors such as ambient temperature.
Covering all bases
Performance relates to the ability to withstand chemical penetration and permeation. In this context, permeation is the process by which a substance moves through the protective clothing fabric on a molecular level. Each fabric will exhibit a degree of resistance to permeation by substances in either a gaseous/vapour or liquid/particulate form. That resistance is determined by measuring two things: a) the permeation rate and b) the breakthrough time. Acceptable results are stipulated by the applicable standards for each protection level or type. The test methods used to determine protection from gases differ from those used for liquids and are governed by the relevant standard.
Permeation rate
The rate at which the hazardous chemical permeates through the test fabric is expressed as a mass of hazardous chemical flowing through a fabric area per unit of time. For example, 1.0 millionth of a gram, per square centimeter, per minute is expressed as: 1.0µg/cm2 /min.
Breakthrough time
Breakthrough time has two sub-definitions; 1. Actual breakthrough time refers to the time between initial contact with the outside surface and detection of the chemical on the inside surface. 2. Normalized breakthrough time is the average time between initial contact with the outside surface and detection on the inside surface at the permeation rate specified by the relevant standard.
Consider construction and other physical attributes
When assessing physical construction, evaluation should also include the fabric technology utilized. Look for a solution with suitable resistance to abrasion or tear and with a greater tensile strength (or break resistance). To determine the requirements, consider the application in terms of the typical range of physical movement likely to be carried out by the wearer.
Utilizing a service such as Ansell’s Chemical Guardian can help clarify selection and deliver optimal safety for workers. Through a personalized assessment, along with recommended permeation times, safety and operations managers can be assured that only the most suitable PPE for the environment is identified, eliminating the likelihood of inappropriate selection and delivering long-term safety and savings. Click here to request for a personalized report.
Story supplied by Ansell Safety Briefing