SAFETY DEVICES AND SYMBOLS IN THE

LABORATORY

SAFE LABORATORY

OPERATIONS AND TECHNIQUES

Chemicals are used everyday.

Accident prevention

- Doing things is not merely the right way, but it is the only way.

Why worry about chemical safety?

Solid reagents are spooned out from the bottle with the use of a clean, dry spatula. They should not be handled with bare hands.

HANDLING SOLIDS

Liquid chemicals are stored in reagent bottles. When pouring a liquid into another container, use a glass rod/stirring rod to prevent the liquid from running down the sides of the container from which it is poured. The glass rod is held against the lip of the container.

POURING LIQUIDS FROM ONE CONTAINER TO ANOTHER

Hold the test tube with a test tube holder tilted at 45 degrees.

Heat the test tube moving it back and forth across the flame.

Do not point the test tube toward anyone.

Do not look into the test tube while it is being heated.

HEATING A LIQUID IN A TEST TUBE

This method is used to separate solid particles from a liquid.

Filter paper is used in the operation

Residue- soil particles that left on the filter paper

Filtrate- water that passes through the filter paper.

FILTRATION

The process of pouring liquid while separating the solid particles.

Supernatant liquid- the liquid obtain from the process.

DECANTATION

Use a watch glass in getting the mass of a liquid.

Do not place a chemical directly on the balance pan

MEASURING THE MASS OF A LIQUID

Safety gown or apronSafety goggles/ lab helmetGlovesWhite mask

SAFETY DEVICES

SAFETY SYMBOLSPoison- substance is harmful, deadly,

and should not be touched, tasted, or inhaled.

Electric shock- indicates that electrical outlets should not be touched when the hands are wet. Electrical apparatus must be disconnected when not in used.

Disposal- used chemicals must be properly disposed of in specific containers.

Hygiene- hands should be thoroughly washed before and after a laboratory activity.

Heating- indicates that one should be extra careful when handling hot materials. One should use gloves, test tube holders, or tongs.