International Programme on Chemical Safety

Guidelines for poison control

II. Technical guidance - 5. Toxicovigilance and prevention of poisoning


Poison information centres have a fundamental role, in partnership with others, in toxicovigilance and prevention. Toxicovigilance consists of the active observation and evaluation of toxic risks and phenomena in the community - an activity that should result in measures aimed to reduce or remove risks. Thus its main goal is prevention.

The role of poison information centres in toxicovigilance includes:

*identifying serious poisoning risks in the local community, and the substances, circumstances, and population groups involved;

*identifying changes in the incidence of poisoning, e.g. different substances of abuse, application of new pesticides, and seasonal variations in the incidence of poisoning, such as carbon monoxide poisoning from heating appliances;

*monitoring the toxicity of commercial products, such as household, industrial, and agricultural chemicals, as well as pharmaceuticals (by any route of administration), for acute, medium-term, and chronic effects, with particular regard to new products and formulations (e.g. overuse of analgesics, occupational exposure to solvents);

*monitoring the toxic effects of drug overdosage;

*identifying substances that cause significant morbidity and mortality, and specific effects on target organs (e.g. high incidence of renal insufficiency, fetal malformations);

*reporting to health authorities and other relevant bodies situations that demand preventive or corrective action, and, where appropriate, calling an alert;

*monitoring the effectiveness of preventive measures.

Where new or altered patterns of poisoning are identified by centres, the data should be strictly verified and evaluated before they are reported to those in charge of community health and regulatory actions and/or to the manufacturers or users of the chemicals involved. Sometimes, this information should also be disseminated at the international level, notably to other poison information centres, professional bodies concerned with toxicology, and organizations such as WHO.

Preventive measures for both individual and multiple cases of poisoning should be established on the basis of the available data on high-risk factors, particularly the circumstances, the substances involved, and the potential victims.

A centre could initiate its preventive activities by reporting information on toxic hazards, identified by toxicovigilance, to those with the authority to take appropriate action, and by giving information and advice to those involved in health education. Further preventive activities could include educational campaigns, producing educational material, and planning, in partnership with others, the implementation and evaluation of preventive measures.

The principal types of preventive action that should be initiated by poison information centres are:

*education, which is a most important part of any action and should be aimed at particular groups at risk, as well as the general public and professional health care workers;

*reports to, and collaboration with, various organizations and institutions on such matters as the development of safer products, safety measures relating to the packaging, design, labelling, transport, and handling of hazardous products, and withdrawing or limiting the availability of selected toxic substances.

Collaboration among all partners in a poison control programme should be strengthened in order to enhance the efficacy of toxicovigilance and preventive actions. The essential partners are:

*poison information centres, facilities for toxicological analysis, and clinical toxicology services, which have a key role in identifying and studying toxicological risks and problems;

*medical and paramedical professionals, such as hospital physicians, general practitioners, occupational physicians, coroners and medico-legal experts, psychiatrists, and pharmacists, all of whom are in a position to collect data that supplement and complement those generated by poison information centres;

*government and local authorities, which have the power to ban or control the use of high-risk chemicals;

*industries, including manufacturers, transporters, and users of chemicals, who should provide the necessary data on the chemicals they handle and cooperate in the implementation of preventive measures;

*universities and research institutions, particularly those concerned with experimental clinical toxicology, which may provide valuable data on chemicals and contribute to their identification and control;

*specialists in mass communications and sociologists, who, in the event of a toxicological emergency, should advise on the appropriate message to the public and its dissemination in a manner that will avoid misunderstandings and alarmism.

Toxicovigilance and prevention programmes

Depending on the facilities that exist in a particular country, minimum programmes for toxicovigilance and prevention should be established initially, with the aim of expanding them later. Such programmes require good basic information about the local situation, including details of acute and chronic poisoning cases, problems of environmental contamination, drug abuse, and circumstances in which there is a high risk of exposure.

Priority should be given to collecting this minimum basic data, which can be done cheaply and reasonably quickly by using:

*data from enquiries received by the poison information centre, which may provide valuable qualitative and quantitative information on cases of poisoning and be used for the evaluation of preventive activities;

*case data from accident and emergency wards, forensic departments, and local hospitals or occupational health clinics;

*technical information on toxic products and their effects, which can be obtained from the literature and other direct sources such as manufacturers and importers of chemicals.

The data collected should permit the identification of local populations at risk and of harmful substances and dangerous circumstances that are likely to play a part in local poisoning cases. This should be helpful for planning appropriate preventive measures.

Documentary resources and other facilities

The minimum documentary resources and physical facilities required are the following:

*textbooks, reviews, manuals, periodicals, and other scientific publications, which would normally be available in poison information centres and which are mostly supplied by medical libraries, manufacturers, importers, and health authorities;

*selected references and periodicals concerning the local situation and needs;

*analysed data on enquiries received by the poison information centre;

*reports of surveys and monitoring carried out by other poison information centres;

*educational material produced by other poison information centres;

*suitable space for conferences and educational events;

*office supplies and equipment;

*simple means for reproducing leaflets and hand-outs.

For maximum effectiveness, however, a programme for toxicovigilance and prevention of poisoning must have comprehensive data on all chemical substances and natural toxins found in the country concerned and appropriate evaluated case data on poisoning (with specific and detailed treatment procedures). Among the additional facilities required are the following:

*statistical and epidemiological data

*a specialized library

*communication facilities, with equipment for monitoring and recording calls

*access to computerized databases

*computers for storage and retrieval of data

*facilities for microfilming

*educational and instructional materials (brochures, posters, slides, videotapes) and facilities for producing them

*space for information resources, data storage, staff administration, and public and professional education.


A minimum programme for toxicovigilance and the prevention of poisoning requires staff with toxicological training and experience. For a full-scale programme, the poison information centre would need, in addition to those running the telephone enquiry service and dealing with patients, a sufficient number of people to follow up enquiries, write reports, and design and implement preventive activities. Training in epidemiology and the use of statistics is highly valuable in view of the type of studies required for toxicovigilance. Staff involved should be familiar with the legislation and regulations concerning the safety of chemical products and be aware of local toxicological problems related to the environment and to veterinary medicine. They should also be taught how to deal with the public, the mass media, and professionals from other fields in order to communicate the message of prevention.

The director of the centre should also:

*have some knowledge of other disciplines relevant to toxicovigilance and the prevention of poisoning;

*be able to supervise the analysis of data and promote epidemiological research;

*ensure that a periodic (at least annual) assessment is made of the evolution of poisoning problems in the country or region concerned and that the relevant authorities are kept informed about preventive measures;

*utilize available data to call an alert on toxicological problems when necessary, enlist the cooperation of relevant partners, and plan effective action;

*ensure that adequate educational material on the prevention of poisoning is prepared for both health care professionals and the public, including material for use in paediatric outpatient clinics, by teachers and children at school, and by doctors in rural hospitals;

*identify sources of funding for preventive activities (e.g. for the publication of colourful, easily understood brochures or posters, and for financing campaigns and educational courses).

Besides the staff of poison information centres, other specialists who should be involved in toxicovigilance and prevention include:

* health educators to design programmes, contact the mass media, and supervise effective continuous distribution of educational material;

* primary health workers to promote prevention at community level;

* psychiatrists to evaluate the incidence and severity of certain types of poisoning (e.g. in suicide attempts) in order to study the possibilities of preventing or minimizing them;

* social workers to evaluate the social conditions that may be determinants in some types of poisoning case, and to advise on ways of getting clear messages to target populations;

* experimental toxicologists to provide experimental data on chemicals and their properties.

Toxicovigilance and poisoning prevention programmes also need the support of adequate administrative and secretarial personnel.


The efficacy of toxicovigilance and of measures for the prevention of poisoning could be considerably enhanced by the implementation of a number of measures at both national and international level.

Recommended action at national level

Efficient communication and coordination between all partners in a poison control programme are primary ingredients for the development of effective national plans for toxicovigilance and prevention. As part of a long-term strategy, adequate knowledge of local poisoning cases should be assembled through data collection and epidemiological investigations. Computerization should facilitate the storage, handling, and rapid analysis of the data. It is therefore essential to promote:

*a system for the centralized registration of poisoned patients treated in hospitals (with diagnostic codes), together with mechanisms for the follow-up of patients in order to identify and evaluate possible medium- and long-term sequelae;

*regulations for the notification of poisoning incidents (e.g. obligatory anonymous reporting of all cases);

*the collection of sound morbidity and mortality statistics with precise certification of death by cause (e.g. from public health systems and forensic departments);

*the pooling of information collected from related areas of mutual interest, e.g. experimental toxicology, analytical toxicology, occupational medicine;

*contacts with industry for the exchange of information on chemical products manufactured and used, and the circumstances and effects of poisoning by these chemicals.

Official support for, and recognition of, the role of poison information centres in toxicovigilance and prevention of poisoning would add weight to the preventive actions instituted by a centre and make it easier for a centre to obtain complete data on the composition of toxic and potentially toxic products. In some cases, legislation providing for the confidential disclosure of the chemical composition of products to poison information centres would be of great value. Legislative authorities should seek the recommendations and advice of poison information centres concerning control measures and legislation to prevent poisoning.

Preventive and educational action may be aimed at the whole community (for example, campaigns for the prevention of poisoning, posters demonstrating the dangers of poisoning by household products and how to avoid them, booklets showing how to recognize poisonous fungi and plants) or specific groups at risk (e.g. on such subjects as pharmaceuticals and pregnancy, the safe use of pesticides by rural workers, and the risks of self-medication in the elderly). Media and communications experts have a vital role in preventive action, since the messages employed should be concise, clearly understandable, and attractive.

The methods employed for preventing, and generating awareness about, poisoning should be adapted to suit national situations and circumstances.

Recommended action at international level

In any country, the problems arising from chemical poisoning are closely linked to geographical, climatic, demographic, economic, and sociocultural conditions. However, tens of thousands of chemicals are in commercial use, and the same chemicals, drugs, or natural toxins may be found in quite different domestic or working environments in different countries, and as contaminants of air, soil, and water. Products containing these chemicals are widely traded throughout the world, and the movement of environmental contaminants does not respect national frontiers.

Many chemicals "travel" when carried by people (e.g. as medicines obtained on holidays, drugs of abuse, insect repellents), and, if unavailable or not in commercial use in a particular country, may be unknown to the local poison information centre. Cooperation between poison information centres in different countries, and with international organizations, may be of value to both national and international programmes for toxicovigilance and the prevention of poisoning.

Poison information centres may arrange to share data on toxic risks, which would permit early warning of potential problems. Pooling of information and expertise in respect of case data on rare, limited, or new phenomena, and of substance data on new hazardous products may enable preventive measures to be taken at an early stage. For the useful exchange of information, it is also essential for collaborators to standardize terminology, agreeing on matters of format and content as well as on the procedures involved in the exchange.

The following are recognized as areas in which international collaboration, through organizations such as IPCS and the World Federation, is needed:

*the exchange between poison information centres and the relevant authorities of bibliographies and documentation on internationally traded formulated products, or on products found outside their country of origin;

*the establishment of centralized or regional systems for the collection and exchange of data on poisoning cases, including their follow-up, and for the assessment, validation, analysis, and storage of these data;

*the establishment of a mechanism for the rapid notification of toxic alerts called in any country and the exchange of experience in dealing with such alerts;

*the exchange of experience of education and training programmes in the field of toxicovigilance and prevention of poisoning;

*the production and dissemination of educational materials on the prevention of poisoning, including material targeted at specific high-risk groups, to be adapted by each centre for local use.