- - AGRICULTURE CORE CURRICULUM - - (CLF2000) Advanced Core Cluster: AGRICULTURAL MECHANICS (CLF2800) Unit Title: EQUIPMENT OPERATION AND MAINTENANCE ___________________________________________________________________________ (CLF2807) Topic: HAZARDOUS AGRICULTURAL Time Year(s) CHEMICALS 1 hour 1 / 2 / 3 / 4 ___________________________________________________________________________ Topic Objectives: Upon completion of this lesson, the students will be able to: Learning Outcome #: (Q-4) - Identify the hazards of working with agricultural chemicals. (Q-5) - Determine what safety standards to follow when using equipment for spreading or spraying hazardous agricultural chemicals. Special Material and Equipment: Labels from hazardous chemicals References: Jacobs, C. O., & Harrell, W. R. (1983).AGRICULTURAL POWER AND MACHINERY. New York: McGraw-Hill. Resources: AAVIM. (1981). APPLYING PESTICIDES. Available from: AAVIM, 745 Gaines School Road, Athens, GA 30605 1-800-228-4689 Free catalog available. Marer, Patrick J. (1988). THE SAFE AND EFFECTIVE USE OF PESTICIDES. University of California, Statewide Integrated Pest Management Project. Available from: Publications, Div. of Agriculture & Natural Resources, Univ. of California, Davis CA 95616 (916) 757-8930 Free catalog available. Evaluation: Quiz by instructor. TOPIC PRESENTATION: HAZARDOUS AGRICULTURAL CHEMICALS A. Machinery Used to Apply Hazardous Agricultural Chemicals (Primarily Pesticides) 1. Chemical application machinery does not have the structural strength, mechanical complexity, and high-energy requirements of tillage, planting, or harvesting equipment. 2. Chemical application equipment needs to be "finely tuned" in order to properly place and distribute chemicals at a specified rate for maximum benefits to production. 3. Proper selection of components and precise calibration, service, and repair are extremely important in the maintenance of machinery used to apply hazardous agricultural chemicals. 4. Hazardous agricultural chemicals are safe, effective, and economical only if they are applied at the correct time, rate, and concentration. 5. Personal and environmental safety precautions should be strictly observed when servicing, maintaining, repairing, or storing equipment that handles hazardous chemicals. a. Equipment should be thoroughly cleaned between each use, before changing from one chemical to another, and before storage. b. Suitable clothing and protection for the eyes, and lungs, should be worn while working with hazardous chemicals. c. Labels on the containers of hazardous chemicals should be read completely and all instructions regarding their use should be followed exactly. B. Worker Safety 1. There are three important chemical poison factors: a. The time span of exposure b. The strength of the poison c. The contact area of the body 2. Regulations establish the format for labels and dictate what information they must contain. a. Labels are legal documents that contain important information for the user. b. Poison strength of a chemical is given in one of four categories. c. Active ingredients of the chemical are listed. d. Instructions for use are given. e. All labels must state, "Keep out of Reach of Children." f. Obtain, read, and understand all of the information on a label and referenced documents before making a pesticide application. 3. Pesticides are grouped into four categories by the Environmental Protection Agency (EPA): a. Category I has the signal words, "Danger-Poison (with a picture of skull and crossbones)," and is lethal in doses of one drop to a teaspoon. b. Category II has the signal word, "Warning," and is lethal in doses of one to two teaspoons. c. Category III has the signal word, "Caution," and is lethal in doses of one ounce to one pint. d. Category IV does not have a signal word and is lethal in doses of one pint to one quart. e. All labels must also state, "Keep Out of Reach of Children." 4. Pesticide toxicity is rated by determining the amount (lethal dose) that will kill 50% of a test population of animals. a. This is referred to as the LD50 (lethal dose that kills 50% of test population); the LD50 is expressed as the milligrams (mg) of pesticide per kilogram (kg) of body weight that will kill 50% of a population of test animals (mg/kg). b. Pesticides that are more toxic present higher hazards, or risks of injury, to people and their environment; special care must be taken when handling these. c. The route of entry (the way it enters the body) will also affect the hazard associated with pesticides. d. Routes of entry into the body include the mouth, skin, eyes, and lungs. C. Drift Control and Environmental Safety 1. Chemical drift is airborne movement and deposit of chemicals to places other than the application area. 2. Drift can be classified by droplet size. (There are 25,400 microns in one inch.) a. A fine aerosol has a 50 micron droplet. b. A fine spray has a 250 micron droplet. c. A medium spray has a 400 to 500 micron droplet. d. A coarse spray has a 600 to 900 micron droplet. 3. Controlling Chemical Drift a. Droplet size is an important factor; use a coarse spray to minimize drift. b. Equipment adjustment is an important factor. 1) Use large nozzles if possible. 2) Keep spray nozzles close to the ground by using wide fan angles. c. Spraying technique and level of operator skill are important factors. 1) Do not spray at more than 40 psi, if possible, and unless it is specifically recommended. 2) Increase ground speed to use larger nozzles. d. The weather is an important factor to consider when applying pesticides. 1) Micro-weather 2) Wind 3) Temperature 4) Inversion layers 4. Contamination Hazards from Chemicals a. People and animals (workers, passers-by, bees, cattle, etc.) can be contaminated by drift. b. Neighboring crops can be contaminated by drift. c. Water (domestic, recreational, and fishing) can be contaminated. 5. Residual Contamination a. Post area when reentry warnings are required (parathion, Systox, etc.). b. Do not flush rigs into drainage channels or streams. _________________________________________________________ ACTIVITY: 1. Read an assortment pf agricultural chemical labels and determine their specific poison category. _________________________________________________________ 6/28/91 OLR/tf #%&C