Accidents in the laboratory.

ACCIDENTS IN THE LABORATORY

They may be caused by:

1. Acids } • Splashes on the skin or • Splashes in the eye

2. Alkalis • Swallowing

3. Toxic substances

4. Heat • Open flames

• Hot liquids

• Inflammable liquids

• Explosions

5. Broken glass

6. Contamination by infected material

7. Electric shock.

The items should be readily available in the laboratory. They must not be kept in a locked cupboard.

First Aid in Laboratory Accidents

Acid Burns

Nitric, sulfuric, hydrochloric and trichloroacetic acids.

In all cases: Wash immediately with large quantities of water.

Acid Splashes on the Skin

a. Wash thoroughly and repeatedly with water.

b. Bathe the affected skin with cotton wool soaked in 5%

aqueous sodium carbonate.

Acid Splashes in the Eye

a. Wash the eye immediately with large quantities of water sprayed from a wash bottle or rubber bulb.

Squirt the water into the corner of the eye near the nose.

b. After washing, put 4 drops of 2% aqueous sodium bicarbonate into the eye.

c. Refer the patient to a physician. Continue to apply bicarbonate solution to the eye while waiting for the doctor. Alternatively, hold the eye under the running tap.

c. Make him gargle with the soap solution.

d. Give him 3 or 4 glasses of ordinary water.

e. If the lips and tongue are burned by the acid:

• Rinse thoroughly with water

• Bathe with 2% aqueous sodium bicarbonate.

Alkali Burns

Sodium, potassium and ammonium hydroxide.

In all cases: Wash immediately with large quantities of water.

Important: Alkali burns are as serious as, and often more

serious than, acid burns.

Alkali Splashes on the Skin

a. Wash thoroughly and repeatedly with water.

b. Bathe the affected skin with cotton soaked in 5% acetic acid (or undiluted vinegar).

Alkali Splashes in the Eye

a. Wash immediately with large quantities of water

sprayed from a wash bottle or rubber bulb. Squirt the water into the corner of the eye near the nose.

b. After washing with water, wash the eye with a saturated solution of boric acid (apply drops repeatedly).

c. Refer the patient to a physician at once.

Swallowing Alkalis

Accidental swallowing while using a pipette:

a. Send for a physician.

b. Make the patient drink at once:

• A 5% solution of acetic acid or lemon juice or

dilute vinegar (1 part vinegar to 3 parts water).

c. Make him gargle with the same acid solution.

d. Give him 3 or 4 glasses of ordinary water.

e. If the lips and tongue are burned by the alkali:

• Rinse thoroughly with water

• Bathe with 5% acetic acid.

Poisoning

This can be caused by:

* Inhaling toxic vapors or gases (e.g. chloroform)

* Accidental swallowing while pipetting a poisonous solution.

In all cases

a. Send for a physician or qualified nurse, specifying the

toxic substance involved

b. Place the victim in the open air while waiting for the

physician.

Burns Caused by Heat

They fall into two categories:

*Severe burns—affecting large areas of skin, e.g. burns caused when burning ether or boiling water is spilled over the victim

* Minor burns—affecting a small area of skin, e.g. burns caused by hot glassware or a Bunsen flame.

Severe Burns

a. If the victim is on fire, e.g. if splashed with burning ether or other inflammable solvent, roll him in a blanket or overall to smother the flames.

b. Inform the physician on duty immediately.

c. Lay the victim on the ground. Do not remove his clothing. Cover him if he is cold.

d. Do not apply any treatment to the burns. This must be left to the physician.

Minor Burns

a. Plunge the affected part into cold water or ice-water to soothe the pain.

b. Apply mercurochrome or acriflavine ointment to the burn.

c. Apply a dry gauze dressing loosely.

d. If the burn becomes infected or does not heal, refer the patient to a physician.

Note: Never tear off the blisters that form over the burns.

Injuries Caused by Broken Glass

These are caused by broken test tubes, syringes or other glassware.

a. Wash the wound immediately to remove any glass pieces.

b. Apply mercurochrome or acriflavine ointment to the wound.

c. Cover with gauze and adhesive tape.

d. If the cut bleeds profusely, stop the bleeding by pressing down on it with a compress. Refer the patient to a physician.

e. If the cut bleeds heavily with the blood spurting out at intervals, try to stop the bleeding with a compress and call a physician or qualified nurse.

f. Continue to press on the wound while awaiting the physician’s or nurse’s arrival. He or she will decide whether a tourniquet should be applied.

Contamination by Infected Material

Wounds caused by broken glassware containing stools,pus, etc.

a. Wash the wound immediately.

b. Check whether the cut is bleeding. If not, squeeze hard to make it bleed for several minutes.

c. Bathe the whole area, i.e. the edges of the cut and inside the cut, with antiseptic lotion.

d. Wash thoroughly with soapy water.

e. Bathe again with antiseptic lotion.

f. Refer the patient to a physician, if the material involved is known to be very infective, e.g. pus.

If infected material is accidentally sucked into the mouth:

a. Spit it out immediately.

b. Wash out the mouth with diluted antiseptic lotion.

c. Wash out the mouth thoroughly with large amounts

of clean water.

Bodily Damage by Electric Shock

A low-voltage alternating electric current (220 V) is usually used in the laboratory and electric shocks are rare. They may occur when faulty equipment is being handled, particularly with wet hands. The symptoms are fainting and asphyxia.

a. Before doing anything else, put off the main switch.

b. Send for a physician.

c. Begin giving mouth-to-mouth respiration immediately

if required.

Precautions for the Avoidance of Accidents

1. Handling acids and alkalis

a. Diluting sulfuric acid with water: Always add the sulfuric acid to the water drop by drop, stirring the mixture after each drop. Do this preferably in a sink. Never pour water into sulfuric acid (because of the danger of splashing).

b. Bottles of acids and alkalis: Keep them on the lower shelves of the cupboards. When you take one out, hold it firmly upright with a dry hand.Do not keep acids and alkalis in bottles with ground glass stoppers as they may get stuck.

c. Pipetting: Where possible, use small measuring cylinders for measuring acids and alkalis. If more accurate measurement is required, use a pipette plugged with non-absorbent cotton wool or with a rubber tube attached. Pipette slowly, watching the level of the liquid.

2. Heating glassware and liquids

a. Test tubes: Never heat the bottom of a test tube.The liquid inside might sputter. Heat the middle of the tube, shaking gently. The mouth of the tube should be facing away from the worker and any other person, towards an empty space or a sink.

b. Ordinary glass and Pyrex: Only Pyrex glassware and porcelain receptacles can be heated over a Bunsen flame. Ordinary glass will break.

c. Inflammable liquids: Only small quantities of inflammable liquids such as ether, ethanol, acetone,benzene, toluene and carbon disulfide should be kept in the laboratory.

Warning: Ether will ignite at a distance of several meters from a flame. Never place a bottle of ether on a workbench where there is an open flame (Bunsen burner, spirit lamp, etc.). Carbon disulfide is even more dangerous.

d. Butane gas: When lighting a gas burner, always light the match and hold it to the burner before turning on the gas tap. Turn off the main valves of all butane gas cylinders every evening. Replace the rubber connecting pipes once a year.

3. Do not use broken, cracked or chipped laboratory

glassware.

4. Put clear labels on poisons. Keep them in a locked cupboard.

5. Do not use nylon clothes while working as these are easily inflammable. Always use a laboratory apron.

6. Always ensure that electrical wiring and electrical appliances are in good condition.

Suggested List of First Aid Equipment for Laboratory

1. 5% aqueous sodium carbonate

2. 2% aqueous sodium bicarbonate in an eye drop bottle

3. 5% acetic acid

4. Saturated solution of boric acid in an eye drop bottle

5. Soap powder solution (5 g per liter of water)

6. Acriflavine ointment

7. Mercurochrome 2%

8. Antiseptic lotion

9. Cotton wool

10. Gauze

11. Roller bandage

12. Adhesive tape

13. Scissors.

Contamination from Infective Material If contamination has occurred, then:

1. Disinfect the part with the disinfectant available in the laboratory. Thoroughly clean the affected area with a stream of running water.

2. Sucking the contaminated material: Spit out all that has been sucked. Use a disinfectant liquid (e.g. diluted dettol) for mouth washing. If the infected material has been swallowed accidentally, forced vomiting to be done, ascertain the kind of infection and take advise from a medical person.

3. If skin is infected by highly virulent organisms, touch the involved part with pure carbolic acid.

Precautionary Measures

1. A fire extinguisher should always be handy.

2. Keep sand bucket in the laboratory.

3. Take measures to prevent electrical short circuiting.

4. No smoking in the working zone of the laboratory.

5. Breakable items should be kept in proper racks and never at the edge of the working table.

6. Do not suck anything with the mouth, use rubber teats and bulbs for sucking.

7. Do not place eatables on the working bench.

8. Keep fingernails short.

9. At the end of the day, clean all working benches with a disinfectant. See that nothing except the required electrical appliance is on.

10. Dispose all infected material properly. Can put such material in hypochlorite solution or in an acidic solution, e.g. diluted sulfuric acid (25%). Burn off all dried contaminated articles, e.g. filter papers.

11. The glassware should be disinfected with a suitable disinfectant and be cleaned thoroughly with running water.

12. Use rubber gloves and a nose mask while working with infective samples, e.g. serum of viral hepatitis patient.

EYE WASHING UPRIGHT

EYE WASHING LYING

MOUTH TO MOUTH RESPIRATION