Safety in the Use of ChemicalsChapter 6Managing Exposure to Chemicals |
Once the risks posed by chemicals to the population and ecology have been assessed, a plan must be drawn up in order to Deal with the consequences of accidental exposures, spills, releases and similar events. Eliminate or minimize the exposure of the population and the ecology of the area, to bring it within safe limits.
Emergency procedures
| While working with chemicals, one should always be prepared to deal with emergencies. |
Emergency situations can be avoided if proper precautionary measures are adopted, but no matter how careful you are, something may go wrong. Decisions made in the crucial moments right when the emergency happens may make the difference between the loss or saving of life and property. The most common types of accidents involving chemicals are:
- Accidental release or spill of a hazardous gas or other chemical.
- Heavy exposure of personnel to a chemical resulting in serious damage to health or injuries.
- Fire or explosion involving chemicals.
Each community should have an emergency plan for dealing with unexpected situations. The exact details of the plan may differ with the toxicity of the chemicals being used and their potential to cause fire and explosions.
Evacuation
The first priority in case of an emergency should be personal safety. In the case a person has been overwhelmed by inhalation of toxic vapours, fumes or smoke or has been affected by fire or splashes of toxic or corrosive chemicals, he should be immediately removed to a safe place, where first aid and medical attention can be given. However, persons involved in evacuation must be properly equipped before they enter the hazardous environment; otherwise they themselves might become a casualty. They must wear adequate personal protective equipment which in most cases would involve a self-contained breathing apparatus. Some essential features of an evacuation plan are:
(i) An alarm system to signal the emergency.
(ii) Unblocked, easily approachable and properly lighted emergency exits.
(iii) Personnel trained in evacuation and rescue procedures.
(iv) Adequate supply of personal protective equipment to the rescuers.
Controlling and dealing with spills or leaks
Detailed information about dealing with leaks and spills of specific chemicals can be found in the safety data sheets. In most cases the immediate step should be to close off the supply of the leaking materials by shutting off a valve or diverting the flow of gases or liquids, depending upon the operation of the process. The spilled material should be dyked, absorbed and disposed of according to the procedures mentioned in the safety data sheets. Basic information about emergency procedures is also usually available on the label of the chemical product. Adequate personal protective equipment must be worn by the persons dealing with the leaks, and the area must be inspected or monitored by qualified personnel before people are allowed in.
First-aid and medical procedures
The basic information about specific first-aid measures to be adopted in case of accidental exposure to a chemical can usually be found in the material safety data sheet or sometimes on the label of the container. All enterprises handling, storing and using chemicals must have arrangements for first-aid in case of accidental exposure. It is even more essential in smaller enterprises, where at least one worker should be trained in administering first-aid, including resuscitation. Adequately provisioned first-aid kits should always be accessible.
Skin exposure
Contaminated clothing should be removed immediately. If removal of clothing proves difficult because of the physical state of the victim or danger of further exposure, then clothes have to be cut away. The affected parts should be rinsed thoroughly with water for at least 15 minutes. Water may not be recommended in the case of chemicals which react with water.
In the case of burns, especially when clothes made from artificial fibres have stuck to the skin, the removal of clothing from the affected part may not be recommended. Only qualified medical personnel can remove these clothes. Emergency showers should be provided near areas where hazardous chemicals are used. If showers are not available, ordinary tap water with glasses, buckets or other containers can be used.
Eye exposure
Chemicals can splash into the eyes during handling and usage. Emergency eye wash showers must be provided near the areas where risks to the eyes exist. Where such showers are not available, clean water from the tap or other sources can be poured from a glass into the opened eyelids and allowed to run out from the outside corners of the eyes. Rinsing should continue for at least 15 minutes, until the irritation goes away. In case the irritation or pain persists after 15 minutes of rinsing, medical attention should be sought.
Inhalation of chemicals
In case of irritation, headache, dizziness and nausea resulting from inhalation of vapours, fumes, dust or gases, the person should immediately move to fresh air. If the condition persists, medical attention should be sought. In case a person becomes unconscious due to inhalation of large amounts of some chemical substance, he should be immediately be removed from the contaminated area and made to lie on his side in the fresh air. Sometimes a supply of oxygen will be needed. If no pulse can be detected, then cardiopulmonary resuscitation (CPR) will be required. Rescuers of victims from contaminated areas must wear self-contained breathing apparatus before entering the area.
The effects of some chemicals may not be evident immediately and the exposed person may develop breathing problems several hours (and in some cases, days) after the exposure. If a person has been exposed to a chemical which can cause delayed effects, he should be kept under medical supervision.
Ingestion
Exposure through ingestion can occur by accident or by consuming contaminated food and drinks or by eating food with contaminated hands. If a person knows that he has swallowed some toxic substance, he should immediately seek medical attention. Vomiting may be induced to get rid of most chemicals. However, many alkalis, acids and organic solvents may do more damage when vomiting is induced. In such cases dilution with water or milk may work. The label of the container or the material safety data sheet should be consulted for specific first aid measures in case of ingestion.
Medical treatment
Some people develop allergies to certain chemicals. They should consult the doctor about the condition if it develops. The work of the physician becomes much easier if he is provided with the product label or material safety data sheet containing the specific information about the hazardous ingredients of the material the person has been exposed to, along with the treatments or antidotes recommended.
Poison control centres
In many countries such centres have been established as a statutory requirement. Most often these are based in major hospitals. Some of these centres can be contacted 24-hours a day by telephone. They have the inventories of most of the toxic chemicals, along with the symptoms of exposure and the specific recommendations doctors for treatment of victims. Some of these centres may have the antidotes to chemical poisoning not commonly available in the market. These centres are an excellent source of information and assistance in emergencies.
Exercise
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