Injurious Substances

• There are various substances used in the lab which are injurious to the health. Everybody should know the hazards and their remedies.

Injurious Substances are:

1. Acids, alkali, and corrosives.
2. Fire.
3. Glassware hazards.
4. Microbial hazards.
5. Equipment hazards.
6. Bad water supply.
7. Explosion.

Chemical substances:

1. These may be acids, alkalies, and corrosives.
2. There may be irritating fumes when there is no adequate ventilation.
3. Injurious Substances may cause:
   1. Irritation.
   2. Severe burns.
   3. Tissue damage.
   4. Chemical burn.
4. Mechanism of the chemical substances causing injury:
   1. When toxic or harmful chemicals are accidentally swallowed by mouth pipetting. This is the reason that mouth pipetting is not allowed in the lab.
   2. When not wearing gloves, the chemical may cause skin injury or may spill into the eye.
   3. In the case of the Ziel-Neelsen stain, when heating the slide and some flammable chemical is lying near that area.
   4. If you spill flammable chemical near the flame.
5. Precautions for use of the injurious chemicals:
   1. During transport put the bottle in a large container or plastic bag.
   2. Never hold the bottle by the neck, always grab it firmly from the body.
   3. During pouring wear eye protection and chemical resistant gloves and gown.
      1. Always use safety eyeglasses.
   4. Store acid in the acid safety cabinet.
   5. Limit volumes of acid to one liter in one container.
6. Always add acid to water and never water to acid.
   1. Mix these solutions always in the sink.
7. Always label properly these bottles.
8. Never allow mouth pipetting.
9. Perchloric acid is explosive when in contact with organic material, and needs careful handling.
   1. Never put this bottle on a wooden bench, always keep it on the glass top.
10. Be careful about handling the mercury, this is poisonous and may spill into the atmosphere.

Compressed Gases:

• These are explosive and lead to severe injury.

Precaution in the use of gases:

1. Label all the gas containers.
2. Leave valve safety covers on until use.
3. Open the valve slowly for use.
4. Label empty tanks.

Liquid Nitrogen:

• It causes freeze injury and severe burns to the skin.

Precaution for liquid nitrogen use: 

1. Use heavy insulated gloves and goggles.

Biological hazards:

1. These are bacterial and viral infections.
2. These are hepatitis viruses and HIV.
3. The possibilities are:
   1. Pathogenic microbes are accidentally ingested.
   2. Pathogenic microbes are accidentally inoculated.
   3. Pathogen microbes are accidentally inhaled from airborne droplets.
4. These can take place from:
   1. Accidental puncture with needles.
   2. By spilling, and splattering the infectious material on the tables or floors.
   3. Spraying of the infectious material.
   4. If there are cuts and scratches from the contaminated blood vessels.
   5. In the case of centrifuge accidents.
   6. Any unfixed tissue like blood slides etc is taken as infectious.
   7. When there is no separate basin for handwashing.
   8. In case there are no rest-rooms to take food and drink. Then these technicians are exposed to infection.
   9. If the lab workers don’t have separate clothes while working in the lab.
   10. When the work table surfaces are not cleaned regularly with antiseptic material.
   11. when there is no facility for the disposal of the infected material

Precautions for the biological hazards:

1. Use barrier protection like gloves, gowns,  and laboratory coats.
2. Use eye mask protection.
3. Use latex gloves as protection. these should be powder-free and low allergen latex.
4. Never use mouth pipetting and also never blow it out if there is the possibility of infectious material.
5. Wash hands after the use of gloves.
6. facial barrier protection is also needed.
7. Dispose of the needle in the rigid container without handling them.
8. Dispose of all sharp material appropriately.
9. Advise frequent hand wash and also wash hands before leaving the lab.
10. Try to make a habit to keep your hands from the eye, mouth, or any other mucous membranes, this will decrease the chances of infection.
11. Decontaminate, and disinfect all useable devices.
12. Be sure that the tubes have no crakes.
13. Periodically clean the fridge and the freezer.

Electrical hazard:

• There are chances for electrical shock.

Precautions:

1. All worn wires should be replaced immediately.
2. Ground all the equipment.

Broken glassware

• The broken test tubes or other glassware needs precautions.

Precaution:

1. Broken test tubes and other glassware are injurious to the lips and hands.
2. These are injurious to the person who is washing and handling this glassware.
3. The best remedy is to remove all these broken glassware.

Toxic fumes

1. In the clinical laboratory when making extracts with a solvent whose vapors are toxic.
2. In the toxicology when extracts with chlorinated hydrocarbons, these cause damage to the liver after a certain time of the exposure.
3. Some of the chemicals are carcinogenic.

Precautions:

1. Always work in the fume hood with good ventilation, particularly when using organic solvents.
2. Avoid contact with skin because these are absorbed by the skin.
   1. wash it with soap and water.
   2. The laboratory should be well ventilated because low concentration exposure for a long period of time is dangerous.

Chemical carcinogens

1. There are a few chemicals that are carcinogenic:
   1. Benzidine.
   2. 2-Acetylaminofluorene.
   3. Ethyleneimine.
   4. Methyl chloromethyl ether.
   5. Beta-propiolactone.
   6. 4-Nitrobiphenyl.
   7. bis-Chloromethyl ether.
   8. N-nitrosodimethylamine
   9. 3,3, Dchlorobenzidine.
   10. 4-Aminodiphenyl.
   11. Alpha-naphthylamine.
   12. O-tolidine.

Precaution:

1. Some of these chemicals are still in use in the clinical laboratory.
   1. e.g. Benzidine for the hemoglobin estimation in the blood.
   2. Try to avoid these carcinogens and use the alternatives.
   3. Use non-carcinogenic compounds.
   4. Don’t spill such chemicals on the table.
   5. If it is powder then try not to inhale it.

Radioactive material

1. These substances are used in the diagnosis and treatment of diseases.

Precautions

1. Carefully store these radioactive materials.
2. Follow the rules and regulations laid down about their storage, workplace, monitoring programs, and disposal.
3. Radiation safety in the people working in such facilities should be followed.
4. In the case of the tracer used in the radioimmunoassay, the radioactivity is very low but still, it needs proper handling and disposal.
5. Gamma rays are penetrating so these materials are kept behind the lead shield.
6. Beta rays are safer and these can keep in their containers and stored in the fridge.
7. Always use disposable gloves when handling these materials to avoid spillover and contamination.
8. Careful disposal of the material is very very important.

Quote

• If you observe reasonable precautions in the clinical laboratory and are equally alert behind the steering wheel.
• You will eventually collect and enjoy your pension as a senior citizen and live longer and die of old age.

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