Safe Handling of Biological and Chemical Hazards

Introduction:

People who work in various laboratories, hospitals, and public health professionals who travel to interior areas as a part of their work are often associated with the risk of contracting injuries and infections after coming in contact with hazardous chemicals and biological agents. Getting exposed to chemical and biological hazards, especially in the work areas, has a major impact on the health of the people exposed to them. The working staff are at high risk of developing skin diseases, contracting infections, cancer, and burns. Inhalation of toxic gas, dust, vapor, and fumes can lead to respiratory problems. Sometimes, the exposure seems inevitable; this process may happen daily, or it can be a single exposure leading to sudden consequences, or the symptoms may develop gradually. Hence, safe handling of such hazardous chemicals and biological agents should be given utmost importance to protect them from their harmful effects, as they are exposed to these hazardous agents regularly.

What Are Biological Hazards?

Biological hazards are the harmful effects of organic agents that cause various health risks and damage to the individuals and other animals exposed to them in day-to-day life (occupational exposure).

What Are the Types of Biological Hazards?

Biological hazards include:

• Viruses like COVID-19, H5N1( bird flu), and Japanese encephalitis.

• Biological toxins.

• Toxins from biological sources.

• Pathogenic microorganisms like fungi, spore-forming bacteria, and viruses.

• Bio-active materials.

• Animal products like blood, tissue, milk, and eggs.

• Human bodily matter like saliva, mucus, and feces.

• Organic wastes like wastewater, sewage, spoiled food, organic dust, and plant wastes.

How Are Biological Hazardous Agents Classified?

1. Group 1 (Poses Low or No Individual or Community Risk): This group consists of biological agents that do not cause any diseases in humans and animals, and hence they are not harmful to the community.

2. Group 2 (Exhibits Moderate Individual Risk or Low Community Risk): This group comprises the microorganisms that cause disease in humans and animals but lack the potential to cause community spread.

3. Group 3 (Poses High Individual Risk and Low Community Risk) - This group consists of agents that cause serious illness in humans and animals, which usually do not spread from one person to another and thus are low-risk biological agents in terms of community spread. However, treatment and preventive aspects should not be neglected.

4. Group 4 (Exhibits Both- High Individual and Community Risk) - This group comprises biological agents that are of great threat to individuals and animals and have the potential to cause community outbreaks. The spread is so severe that the available treatment and preventive measures can not contain the disease.

What Are Chemical Hazards?

Chemical hazards occur as a result of exposure to harmful chemicals, which can be solid, liquid, or gas, and these chemicals cause adverse effects in individuals who come in contact with them. The chemical agent can be a single ingredient or a pure substance, or it can be a mixture of two or more substances.

What Are the Types of Chemical Hazards Encountered?

Chemical hazards are divided into chemical and physicochemical hazards.

Chemical Hazards:

• Carcinogens.

• Skin irritants.

• Respiratory irritants.

Physicochemical Hazards: They occur owing to the physical or chemical properties of a chemical agent.

• Corrosive substances.

• Chemical explosions.

• Unexpected chemical reactions.

What Are the Steps Adopted in Safe Handling of the Biological and Chemical Hazardous Agents?

Protective Measures to Prevent Ill-Effects of Biological Hazards:

Protective Clothing:

• A person working in a lab should wear protective clothing and should be changed regularly and immediately if contaminated.

• These gowns or protective clothing should not be worn outside the lab to prevent cross-contamination. The person needs to change and then step out.

• High-quality gloves with good resistance have to be worn, and double gloves should be worn if there is a high chance of being torn when handling highly infectious agents.

• Wearing a facemask or eye-protective glasses is compulsory when working on an open bench.

Immunization:

• All the laboratory personnel should be compulsorily immunized against tetanus.

• People who deal with human tissues and blood should be immunized against hepatitis B without fail.

Reporting of an Accident:

• Occupation-related accidents should be addressed immediately by allowing the wound to bleed, which is followed by washing with soap thoroughly. Also, scrubbing of the wound is to be avoided.

• A waterproof dressing should be given to the wound, and in case of exposure to skin, eye, or any other mucous membrane, thorough cleansing of the affected part should be done.

Working In Respective Workplaces:

• The workplace should be free from all harmful agents and should be fumigated to destroy all the possible pathological aerosols at the end of the day and ensure a safe work area for the next day.

• The workplace should be cleared of unnecessary equipment, and all the surfaces should be disinfected soon after the work completion.

Laboratory Equipment:

• All the apparatus and equipment should be disinfected at the end of the day after the accomplishment of the work.

• If any equipment is subjected to maintenance work, it should undergo decontamination priorly.

• Centrifuged samples carrying various infectious materials should be transported in sealed buckets or rotors.

• These sealed buckets or rotors should be opened in a safety cabinet.

• The seals of the transport media should be evaluated for any damage or wear and need to be replaced immediately in case of wear and tear to protect the environment from getting contaminated.

Handling Human-Tissue Samples:

• Human tissue samples should be handled in a bio lab, which is equipped with various biosafety chambers.

• All the suspected samples are considered infective and are processed under a containment level 2 facility (bio lab where highly infectious materials are handled).

• In case of an encounter with an HIV sample (human immunodeficiency virus), the work needs to be stopped immediately and should be shifted to more advanced bio labs.

Protective Measures to Prevent Ill-Effects of Chemical Hazards:

While Using Chemicals:

• Necessary measures and precautions should be taken well in advance when using any chemical, and SDS (safety data sheet) should be consulted before handling any hazardous chemical.

• If any chemical is spilled, it should be cleared as soon as possible to prevent environmental exposure.

• The chemical, after its use, should not be kept at the workplace; instead, it should be placed back in its place to avoid accidental spills and exposure.

Storing of Hazardous Chemicals: Storing chemicals often results in physical hazards following a toxic reaction, which occurs when highly hazardous chemicals are stored in a place, causing occupational risks to the staff who work in such environments. Hence, it becomes the utmost responsibility of every staff who handles such chemicals to wear personal protective equipment whenever they work with such agents and use safety measures to prevent accidents in the workplace. Certain chemicals, when stored, react with the local atmosphere and lead to physical hazards at the workplace. Some of them include:

Flammable Substances :

• Flammable and combustible chemicals are dangerous as they emit vapors below 38 degrees Celsius and above 38 degrees Celsius, respectively, and cause explosion if they come in contact with the ignition source, as these vapors are invisible.

• Flammables are more dangerous at high temperatures as they become more volatile and should be stored carefully.

• Also, these chemicals should be kept away from sparks from welding or cutting instruments, hot surfaces, and electrical equipment.

• Fire extinguishers should be kept ready to address unexpected explosions.

Corrosive Chemicals:

• These chemicals cause skin burns owing to their corrosive nature.

• The laboratory personnel should wear personal protective equipment while handling such caustic chemicals.

• When diluting the concentrated acids, the acid should be poured slowly into the water, and avoid adding water to the acid as it causes a sudden reaction and leads to corrosion.

• The caustic chemicals, especially acids and bases, need to be stored separately from each other.

Oxidizing Chemicals:

• These chemicals are highly reactive and lead to the combustion of flammable and combustible chemicals as they produce oxygen gas, leading to unexpected chemical accidents.

• Keeping the chemicals away from the workplace initiates a chemical reaction.

• Always have the shield and other protective equipment ready to use in case of unexpected explosions or accidents.

• Ensure not to exceed the quantity required for conducting the experiments.

• Oxidizing chemicals need to be stored away from flammable, organic, and reducing chemicals.

• Caustic agents like perchloric acid should be kept in perchloric acid fume hoods to prevent the deposition of perchlorate fumes deposition as they are shock-sensitive.

Conclusion:

Occupational risks involve both biological and chemical health hazards, which can be prevented by carrying out good hygiene practices and safety precautionary measures. Various awareness programs are conducted to create the importance of practicing good hygiene and precautionary measures in safeguarding one’s health against risky exposures and infectious diseases from spreading to one another. Every laboratory personnel should undergo training in laboratory practice to ensure the smooth functioning of the workplace and be able to protect themselves and others from unnecessary occupational health risks.