IPCS INTERNATIONAL PROGRAMME ON CHEMICAL SAFETY Health and Safety Guide No. 47 ATRAZINE HEALTH AND SAFETY GUIDE UNITED NATIONS ENVIRONMENT PROGRAMME INTERNATIONAL LABOUR ORGANISATION WORLD HEALTH ORGANIZATION WORLD HEALTH ORGANIZATION, GENEVA 1990 Published by the World Health Organization for the International Programme on Chemical Safety (a collaborative programme of the United Nations Environment Programme, the International Labour Organisation, and the World Health Organization) This report contains the collective views of an international group of experts and does not necessarily represent the decisions or the stated policy of the United Nations Environment Programme, the International Labour Organisation, or the World Health Organization WHO Library Cataloguing in Publication Data Health and safety guide for Atrazine (Health and safety guide ; no. 47) 1.Atrazine - standards I.Series ISBN 92 4 151047 1 (NLM Classification: WA 240) ISSN 0259-7268 The World Health Organization welcomes requests for permission to reproduce or translate its publications, in part or in full. Applications and enquiries should be addressed to the Office of Publications, World Health Organization, Geneva, Switzerland, which will be glad to provide the latest information on any changes made to the text, plans for new editions, and reprints and translations already available. (c) World Health Organization 1990 Publications of the World Health Organization enjoy copyright protection in accordance with the provisions of Protocol 2 of the Universal Copyright Convention. All rights reserved. The designations employed and the presentation of the material in this publication do not imply the expression of any opinion whatsoever on the part of the Secretariat of the World Health Organization concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. The mention of specific companies or of certain manufacturers' products does not imply that they are endorsed or recommended by the World Health Organization in preference to others of a similar nature that are not mentioned. Errors and omissions excepted, the names of proprietary products are distinguished by initial capital letters. CONTENTS INTRODUCTION 1. PRODUCT IDENTITY AND USES 1.1. Identity 1.2. Physical and chemical properties 1.3. Analytical methods 1.4. Production and uses 2. SUMMARY AND EVALUATION 2.1. Human exposure to atrazine 2.2. Uptake, metabolism, and excretion 2.3. Effects on animals 2.4. Effects on human beings 2.5. Effects on the environment 3. CONCLUSIONS AND RECOMMENDATIONS 4. HUMAN HEALTH HAZARDS, PREVENTION AND PROTECTION, EMERGENCY ACTION 4.1. Main human health hazards, prevention and protection, first aid 4.1.1. Prevention and protection 4.1.2. First aid 4.2. Advice to physicians 4.3. Explosion and fire hazards 4.4. Storage and transport 4.5. Spillage and disposal 5. HAZARDS FOR THE ENVIRONMENT AND THEIR PREVENTION 6. CURRENT REGULATIONS, GUIDELINES, AND STANDARDS 6.1. Exposure limit values 6.2. Specific restrictions 6.3. Transport and labelling INTRODUCTION This Health and Safety Guide is not based on an existing Environmental Health Criteria document, but on critical national reviews. The hazard evaluation in the Health and Safety Guide was made on the basis of carefully selected studies, after scrutiny of the original publications. In order to assist the peer-review process of the present Health and Safety Guide, a background companion document was prepared by the IPCS and can be obtained from the Manager on request; the IPCS does not intend that the background document should be published. The first three sections of this Health and Safety Guide present essential technical information and the hazard evaluation. Section 4 includes advice on preventive and protective measures and emergency action; health workers should be thoroughly familiar with the medical information to ensure that they can act efficiently in an emergency. The section on regulatory information has been extracted from the legal file of the International Register of Potentially Toxic Chemicals (IRPTC) and from other United Nations sources. The target readership includes occupational health services, those in ministries, governmental agencies, industry, and trade unions who are involved in the safe use of chemicals and the avoidance of environmental health hazards, and those wanting more information on this topic. An attempt has been made to use only terms that will be familiar to the intended user. However, sections 1 and 2 inevitably contain some technical terms. Revision of the information in this Guide will take place in due course, and the eventual aim is to use standardized terminology. Comments on any difficulties encountered in using the Guide would be very helpful and should be addressed to: The Manager International Programme on Chemical Safety Division of Environmental Health World Health Organization 1211 Geneva 27 Switzerland THE INFORMATION IN THIS GUIDE SHOULD BE CONSIDERED AS A STARTING POINT TO A COMPREHENSIVE HEALTH AND SAFETY PROGRAMME 1. PRODUCT IDENTITY AND USES 1.1 Identity Common name: atrazine Chemical formula: C8H14ClN5 Chemical structure:Relative molecular 215.7 mass: Common trade A 361; Aatrex; Aatrex 4L; Aatrex 80W; Aatrex names (including Nine-O; Aktikon; Aktikon PK; Aktinit A; formulations): Aktinit PK Argezin; Atazinax; Atranex; Atrasine; Atratol A; Atrazin; Atred; Atrex; Candex; Cekuzina-T; Crisatrina; Crisazine; Cyazin; Farmco Atrazine; Fenamin; Fenamine; Fenatrol; G 30027; Geigy 30,027; Gesaprim; Gesoprim; Griffex; Hungazin; Hungazin PK; Inakor; Oleogesaprim; Primatol; Primatol A; Primaze; Radazin; Radizine; Strazine; Triazine A 1294; Vectal; Vectal SC; Weedex A; Wonuk; Zeazin; Zeazine CAS chemical name: 2-chloro-4-ethylamine-6-isopropylamino- S- triazine Synonyms: S-triazine, 2-chloro-4-ethylamino- 6-isopropylamino-; 1,3,5-triazine-2,4- diamine, 6-chloro- N-ethyl- N'- (1-methylethyl)-; 2-aethylamino-4- isopropylamino-6-chlor- 1,3,5-triazin; 2-chloro-4-ethylamineiso-propyl- amine- S-triazine; 1-Chloro-3-ethylamino-5- isopropyl-amino-2,4,6-triazine; 1-chloro-3-ethylamino-5-isopropyl-amino- S- triazine; 2-chloro-4-ethylamino-6-isopropyl- amino- 1,3,5-triazine; 2-chloro-4-ethylamino-6-isopropyl- amino- S-triazine 6-chloro- N-ethyl- N'-(1-methylethyl)-1,3,5-triazine- 2,4-diamine; 2-chloro-4-(2-propylamino)- 6-ethylamino- S-triazine CAS registry number:
1912-24-9 RTECS registry number: XY5600000 According to FAO specifications, commercial atrazine should be at least 92% pure, and most products are about 95% pure. Common impurities are sodium chloride and other symmetric triazines, such as simazine and propazine. It is often formulated as wettable powders, granules, and as flowable suspensions. Wettable powder formulations contain 450-800 g atrazine/kg (less if mixed with other pesticides), and liquid formulations (including suspension concentrate), 40-650 g/litre. 1.2 Physical and Chemical Properties Technical atrazine is a colourless crystalline powder with low vapour pressure (40 nPa at 20°C). A melting point range of 175-177°C has been reported for the technical product. It is readily soluble in dimethyl sulfoxide (183 g/litre), moderately soluble in methanol (18 g/litre), diethyl ether (12 g/litre), chloroform (52 g/litre), and ethyl acetate (28 g/litre), and very slightly soluble in water (30 mg/litre). It is stable in the dry state, but is hydrolysed to the herbicidally inactive 2-hydroxy analogue in acid or in alkaline solutions and more slowly in neutral aqueous solutions, even at elevated temperatures. 1.3 Analytical Methods Gas chromatography with a nitrogen-phosphorus detector (NPD) is used for the determination of residues and the analysis of environmental samples. The minimum detection limit varies according to the substrate. 1.4 Production and Uses Atrazine was introduced in 1958. In 1987, total worldwide production was estimated to be 70 000 tonnes. Atrazine is a selective pre- and post-emergence herbicide used for the control of weeds in crops, such as asparagus, corn, sorghum, sugar cane, and pineapple. It is also used in forestry and, at higher application rates, for non-selective weed control in non-crop areas. 2. SUMMARY AND EVALUATION 2.1 Human Exposure to Atrazine Highest human exposure to atrazine is associated with its production and its use in agriculture. Widespread, low-level exposure of the general population may occur through contaminated drinking-water. 2.2 Uptake, Metabolism, and Excretion Atrazine is readily absorbed from the gastrointestinal tract, but only penetrates the skin to a very limited extent. The absorbed herbicide is rapidly eliminated. In the rat, the whole-body half-life is about 1.3 days, and 95% of the dose is eliminated within 7 days. The highest concentration of atrazine and/or its metabolites is found in the red blood cells, to which the triazines bind effectively. In rats given low, oral doses, daily, levels were found in the tissues in the following decreasing order: erythrocytes, liver, spleen, kidney. The primary route of elimination in rodents is via the urine (about 75%); approximately 20% is eliminated in the faeces. Dealkylation at the C-4 and C-6 positions of the atrazine molecule are the principal metabolic degradation reactions. Dechlorination at the C-2 position also occurs, to some extent. In the rat, the major urinary metabolites include the two mono- N-dealkylated metabolites and the fully dealkylated derivative, 2-chloro-4,6-diamino- S-triazine. 2.3 Effects on Animals The acute oral toxicity and the dermal toxicity of atrazine in rodents are both low. Acute oral studies conducted on different rodent species have indicated LD50 values in the range of 1700-4000 mg/kg. Young rats are much less sensitive to atrazine than adults. Ruminants seem to be much more sensitive to the acute toxic action of atrazine than rodents. In one study, 2 doses of 250 mg/kg caused death in both sheep and cattle. The irritant action of atrazine is only slight on rabbit skin, but is moderate for the rabbit eye. Atrazine has been subjected to extensive long-term testing on rats, mice, and dogs. Significant cardiac toxicity was observed in dogs after long-term oral administration of atrazine at doses of 5 mg/kg per day or more. In rats and mice, reduced food intake, decreased weight gain, and toxic effects on other organs were detected after long-term administration of atrazine at high dose levels (> 25 mg/kg per day). These effects included muscle degeneration, retinal degeneration, necrosis of the liver, and haematological effects in rats and in mice. An increase in mammary tumours was observed in rats, but not in mice. Taking into account the very high background level of mammary tumours in untreated animals, the compound's apparent lack of genotoxicity, and the fact that the maximum tolerated dose was exceeded, these findings do not represent convincing evidence of carcinogenicity. Atrazine exerts a fetotoxic action at, or close to, dose levels that have a deleterious action on the mothers, but does not seem to have any significant teratogenic action in rats, mice, or rabbits. 2.4 Effects on Human Beings There are no substantiated indications that atrazine causes any health or safety hazards for the general population or for exposed workers. 2.5 Effects on the Environment On the basis of acute and short-term dietary studies, the toxicity of atrazine for birds is low, with no mortality at 10 000 mg/kg diet. Atrazine is virtually non-toxic for bees, but is moderately toxic for aquatic organisms (96-h LC50 range from 0.5 to 15 mg/litre). The herbicide is degradable and has little tendency to bioaccumulate, thereby limiting possible long-term adverse effects on wildlife and fish. As it is an effective herbicide, its phytotoxicity may constitute a problem in the case of uncontrolled applications. However, the main concern is its relative persistence (half-life of 125 days in sandy soils) and mobility in some types of soils (related to rainfall), resulting in contamination of surface and ground waters. 3. CONCLUSIONS AND RECOMMENDATIONS The acute oral and dermal toxicities of atrazine for most mammalian species are low. Atrazine has no significant teratogenic action in rats, mice, or rabbits. There is no convincing evidence of carcinogenicity in rats or mice. Toxic effects, including ocular, cardiac, haematological, and hepatic effects, have been observed in both rats and mice after long-term administration. On the basis of acute and short-term dietary studies, the toxicity of atrazine is low for birds and moderate for aquatic organisms. It has a low capacity for bioconcentration. The relative persistence and mobility of atrazine in some types of soils can result in contamination of ground and surface waters. It is recommended that adequate precautions should be taken to prevent this contamination. A few gaps in data have been identified that indicate a need for further mutagenicity testing and studies of the mechanism of tumour induction in rats. Atrazine is moderately irritating to the eye. No significant health effects on either the general population or exposed workers are expected. 4. HUMAN HEALTH HAZARDS, PREVENTION AND PROTECTION, EMERGENCY ACTION 4.1 Main Human Health Hazards, Prevention and Protection, First Aid The acute toxicity of technical atrazine for human beings is thought to be low, and no adverse health effects from exposure to this herbicide have been reported. In view of the toxicity induced in experimental animals on repeated exposure, proper care should be taken during occupational use to avoid excessive inhalation of dust or spray particles, and to prevent accidental contamination of food products and water. 4.1.1 Prevention and Protection In order to reduce the risk of accidental contamination, the following precautions should be observed during handling and use: (a) Avoid contact with the skin and eyes. (b) Do not smoke, drink, or eat in the work-place. Wash hands and any exposed skin before eating, drinking, or smoking, and after work. (c) Avoid raising a dust cloud when handling wettable powder formulations. (d) Avoid breathing dust from powder products. (e) When unloading and handling containers, wear protective PVC or neoprene gloves. (f) When handling leaking containers, or when dealing with leaks and spills, wear overalls and PVC or neoprene gloves and boots. If overalls become contaminated, change and wash them thoroughly before re-use. (g) Store products in dosed original containers, out of reach of children, and away from food, drink, and animal feed. 4.1.2 First Aid Poisoning by atrazine is unlikely, unless large amounts have been ingested. In case of over-exposure, apply routine first-aid measures. If material has been spilled on the skin, immediately remove the patient from the source of contamination, remove all contaminated clothing, and wash affected areas with soap and running water. If the material is in the eyes, flush with clean water for at least 15 minutes. In case of ingestion of significant quantities, and, if the patient is conscious, give a glass of water and subsequently administer activated charcoal. Do not induce vomiting. In serious cases, medical attention should be sought. 4.2 Advice to Physicians The acute toxicity of atrazine for human beings is believed to be low. There is no specific antidote. Treat symptomatically when required. When large amounts have been ingested, gastric lavage may be indicated. 4.3 Explosion and Fire Hazards Technical atrazine is not flammable but, on heating, it decomposes to form toxic fumes containing oxides of nitrogen (NOx) and hydrogen chloride (HCl). Extinguish small fires with carbon dioxide, dry powder, or alcohol-resistant foam. Water spray can be used for larger fires and the cooling of unaffected stock, but avoid the accumulation of polluted run-off from the site. Beware: Some liquid formulations may be highly flammable and require alcohol-resistant foam as an extinguishing agent. 4.4 Storage and Transport All products should be stored in secure buildings, out of reach of children and animals, and local regulations should be complied with. Containers should be sound and adequately labelled. 4.5 Spillage and Disposal Keep spectators away from any leakage. Prevent contamination of other goods or cargo, or nearby vegetation and waterways. Absorb spilled liquid products with sawdust or sand, sweep up and place in separate container. Empty any product remaining in damaged or leaking containers into a clean empty container, which should be suitably labelled. Sweep up any spilled powder with damp earth or sand or other suitable absorbent, such as sawdust, taking care not to raise a dust cloud (use a vacuum cleaner). Place in separate container for subsequent disposal. Contaminated absorbents, used containers, surplus product, etc., should be burnt in an incinerator, preferably designed for pesticide disposal. Hydrolysis under alkaline conditions (10% w/v sodium hydroxide) is a suitable method to dispose of small quantities of atrazine. Heating speeds the process. After hydrolysis, dilute and dispose of via the sewage system. Atrazine is relatively stable and characterized by high mobility in some soils and should not be buried in dump sites, etc. Comply with any local legislation applying to waste disposal. 5. HAZARDS FOR THE ENVIRONMENT AND THEIR PREVENTION Triazines may be ingested by domestic animals. In view of the relatively high toxicity of atrazine for ruminants, exposure to atrazine of sheep and cows should be avoided. Because of its relative persistence and mobility in some types of soils, atrazine has a significant potential for contamination of ground and surface waters. The contamination of ponds, waterways, and ditches should be avoided. 6. CURRENT REGULATIONS, GUIDELINES, AND STANDARDS The information given in this section has been extracted from the International Register of Potentially Toxic Chemicals (IRPTC) legal file. A full reference to the original national document from which the information was extracted can be obtained from IRPTC. When no effective date appears in the IRPTC legal file, the year of the reference from which the data are taken is indicated by (r). The reader should be aware that regulatory decisions about chemicals, taken in a certain country, can only be fully understood in the framework of the legislation of that country. Furthermore, the regulations and guidelines of all countries are subject to change and should always be verified with the appropriate regulatory authorities before application. 6.1 Exposure Limit Values Exposure limit values for atrazine are given in the following table. 6.2 Specific Restrictions The National Swedish Chemicals Inspectorate has recently announced its intention to prohibit the use of atrazine and other triazine herbicides for weed elimination on gravel roads and similar surfaces. Atrazine constitutes a contaminant required to be regulated by the US Safe Water Drinking Act of 1986, including the promulgation of a MCLG (Maximum Concentration Limit Goal). 6.3 Transport and Labelling The United Nations Committee of Experts on Transportation of Dangerous Goods classifies atrazine in: - Hazard Class 6.1: poisonous substances; - Packing group III: substance presenting a relatively low risk of poisoning in transport. EXPOSURE LIMIT VALUESa Medium Specification Country/ Exposure limit description Value Effective organization date AIR Occupational Australia Time-weighted average (TWA) 5 mg/m3 1983 Belgium Time-weighted average (TWA) 5 mg/m3 1988 Germany, Federal Time-weighted average (TWA) 2 mg/m3 1988 Republic of, - Maximum worksite concentration 2 mg/m3 Switzerland Time-weighted average (TWA) 10 mg/m3 1987 United Kingdom Maximum allowable concentration 2 mg/m3 1977 USSR (Ceiling value) WATER Drinking- Canada Interim maximum acceptable 0.06 mg/litre 1987 concentration EEC Maximum allowable concentration 0.1 µg/litre Switzerland Maximum residue limit 0.1 µg/litre 1980 WHO/EURO Guideline value 2.0 µg/litre 1987 WATER Oral intake WHO/EURO Acceptable daily intake (ADI) 0.7 mg/g 1987 body weight FOOD Plant (general) EEC Maximum residue limit 0.1 mg/kg FOOD Plant (specified) Brazil Acceptable limit 0.1-0.2 mg/kg 1984 EXPOSURE LIMIT VALUESa (cont'd). Medium Specification Country/ Exposure limit description Value Effective organization date FOOD Plant (general) Germany, Federal Maximum residue limit 0.1 mg/kg 1984 Republic of, Plant (specified) Germany, Federal Maximum residue limit 0.5-10 mg/kg 1984 Republic of, FOOD Specified food Kenya Maximum limit 0.02-0.25 mg/kg products FOOD Raw agricultural USA Tolerance (Acceptable residue limit) 0.02-15 mg/kg 1982 products (specified plant and animal products) Oral intake USA Reference dose 0.005 mg/kg body weight FOOD Specified food USSR Acceptable daily intake (ADI) 0.004 mg/kg 1983 products FOOD Oral intake USA Tolerance 0.005 mg/kg GOODS Brazil Use in domestic sanitation not authorized a For other regulatory data see complete legal file of IRC data profile. The label should be as follows:The European Economic Community legislation requires labelling as a dangerous substance, using the symbol:
The label must read: Harmful by inhalation, in contact with the skin, and if swallowed; keep out of reach of children; keep away from food drink; and animal feed.
See Also: Toxicological Abbreviations Atrazine (ICSC) Atrazine (IARC Summary & Evaluation, Volume 53, 1991) Atrazine (IARC Summary & Evaluation, Volume 73, 1999)