Hazards during Chemicals in Use and Safety Guidelines

During Chemicals in Use

The Hazards and the Consequences

Key Steps in Safe Use of Chemicals

Know the Hazards

Understand the hazardous properties of the chemicals involved

Understand the reaction and the products during chemicals in use May the process generate heat and/or gases?

Is there any side reaction involved? What are the side products?

Are the products dangerous substances? What are the hazardous properties?

Understand the effect of the environment to the reaction, the reactants and the products

May light, heat and shape of the container affect the reaction so that it will be out of control?

May light, heat, air and water affect the reactants and the products so that other reactions will occur?

Safety measures Select other safer substitutes or procedures

Use engineering control measures - including ventilation and exhaust system, temperature control, stirring facility, appropriate

container

Wear appropriate personal protective equipment

Understand and follow safe operating procedures - including procedures for use of engineering control and personal protective equipment and for

waste disposal

Understand contingency measures, and in case of accident follow emergency procedures

- including procedures for firefighting, evacuation, first aid, Treatment of spillage

How can we obtain hazard and safety information? Read the label and material safety data sheet

(MSDS) of the chemicals Obtain information from other references, such as

handbooks on chemical safety

Dos and Don'ts in Safe Use of Chemicals Know the hazard before using the chemicals

Before using the chemicals, the hazardous properties of all chemicals involved and the possible hazards at every stage of the process should be fully understood. Appropriate safety measures can then be taken.

Use appropriate control measures and personal protective equipment Appropriate control measures (such as engineering control) should be used to reduce

the exposure to the hazard to the lowest level. Personal protective equipment should only be a supplement to, and not in lieu of, control measures, and should be selected appropriate to the hazards to be encountered.

Keep the work area well-ventilated, or even work under local exhaust ventilation

Always keep the work area well-ventilated to avoid accumulation of hazardous gas/vapor. Increase the ventilation by mechanical means if necessary. In case where more hazardous chemicals or processes are encountered, work under local exhaust ventilation.

Keep away from any ignition source when handling flammable substances Ignition source may ignite the vapor of the flammable substance, and even lead to

explosion.

Don't eat, drink and smoke Dangerous substances can easily enter the body while eating, drinking or

smoking during use of chemicals, and would be injurious to health.

Don't touch chemicals with bare hands. Wear protective gloves. Dangerous substances can easily enter the body through the skin while touching

chemicals with bare hands, and would be injurious to health. If the chemical is corrosive, the hands will suffer from chemical burn. Appropriate protective gloves should be worn.

Don't suck chemicals with your mouth. Use appropriate liquid delivery tools. Dangerous substances can easily enter the body during sucking chemicals with

mouth, and would be injurious to health. If the chemical is corrosive, the mouth will suffer from chemical burn. Appropriate liquid delivery tools such as hand pumps should be used

Don't use container with narrow opening for a process that evolves heat and/or gases

As the opening of the container is narrow, the releasing gas bubble may carry along hot liquid out of the container. At the same time, the heat and gas generated may tremendously increase the pressure inside the container which consequently burst. It will be more hazardous if dangerous substances are involved.

Don't mix oxidizing agents with flammable /combustible substances When oxidizing agent such as potassium permanganate is in contact

with flammable / combustible substance, including sculpture powder, carbon powder, zinc dust, wood dust, etc., vigorous oxidation reaction may occur Spontaneously evolving large amount of heat and possibly gases. This may also lead to fire and explosion.

Don't mix acid with bleaching solution When bleaching solution is mixed with acid, reaction occurs

spontaneously liberating toxic gases.

Beware of Hazards during Chemicals in Use

Grinding solids into powder form: Beware of inhaling dangerous substances and causing explosion

During grinding solids, the chemical in powder form may become airborne and easily enter the human body by inhalation. If the chemical is a toxic/harmful/irritating substance, it will be injurious to health. In addition, during the grinding process some explosive chemicals (such as peroxides) can cause explosion under friction or shock.

Grinding solids into powder form: Beware of inhaling dangerous substances and causing explosion

During grinding solids, the chemical in powder form may become airborne and easily enter the human body by inhalation. If the chemical is a toxic/harmful/irritating substance, it will be injurious to health. In addition, during the grinding process some explosive chemicals (such as peroxides) can cause explosion under friction or shock.

Pouring powdered chemicals into another container: Beware of inhaling dangerous substances and causing fire/explosion

During pouring powdered chemicals into another container, the chemical in powder form may become airborne and easily enter the human body by inhalation. If the chemical is a toxic/harmful/irritating substance, it will be injurious to health. In addition, airborne particles of combustible chemicals and easily ox disable metals form flammable mixtures when mixed with air. The flammable mixtures catch fire in the presence of an ignition source and even lead to explosion.

Safe practices - No source of ignition is allowed nearby during operation ! - Operate under local exhaust ventilation to vent away hazardous

airborne particles. - Wear personal protective equipment such as respirator, gloves as

appropriate.

Using a sprayer to spray chemicals: Beware of inhaling dangerous substances and causing fire/explosion

During spraying, the chemical in aerosol form may enter the human body by inhalation or skin contact. If the chemical is a toxic/harmful/irritating substance, it will be injurious to health. Besides, propellants used in common aerosol cans are flammable substances, and if the chemical being sprayed is a combustible substance, the aerosol of the chemical may form flammable mixtures with air. The flammable mixtures catch fire in the presence of an ignition source and even lead to explosion.

Safe practices No source of ignition is allowed nearby during operation !

Operate under local exhaust ventilation to vent away the hazardous aerosol as far as practicable. If this is not practicable and the work with less hazardous chemical is of short duration, ensure that the place is well-ventilated.

Wear personal protective equipment such as respirator, face mask, protective clothing, and gloves as appropriate.

Heating liquids: Beware of splashes of superheated liquid and inhaling hazardous vapors In the

absence of nucleus for bubble formation in the container, the liquid under heating may not appear to boil even though the temperature exceeds the boiling point. This is the superheating

phenomenon. However, when the liquid is disturbed such as lifting the container bubbles form spontaneously and rush out, leading to splashing of the hot liquid. In addition, if the chemical involved is a dangerous substance, the hazardous vapor evolved during heating will be injurious to health when inhaled.

Safe practices Don't use microwave oven to heat liquids!

Add pieces of stones to the liquid prior to heating as far as practicable or constantly stir the liquid during heating. This helps bubble formation and avoids superheating.

Operate under local exhaust ventilation to vent away hazardous vapors as far as practicable. If this is not practicable and the chemical is less toxic, ensure that the place is well-ventilated.

Wear personal protective equipment such as gloves, eye protection, respirator as appropriate.

Pouring flammable liquids to another container:Beware of fire/explosion Pouring flammable liquids (such as petrol, acetone, etc.) from one container to another

activates vaporization of the flammable material. At the same time, friction between the liquid flow and the container as well as air may generate static electricity. Spark forms when discharge occurs. The spark ignites the flammable vapor in the vicinity. Consequently the flammable liquid will be on fire and may even lead to explosion.

Safe practices

No source of ignition is allowed nearby !

Operate under local exhaust ventilation to vent away the flammable vapor as far as practicable. If this is not practicable and the chemical is less hazardous, ensure that the place is well-ventilated.

Connect the containers to earth by a conducting wire so as to avoid spark discharge.

Any clothing contaminated with flammable substance during the process should be taken off and should be properly treated, such as venting off the flammable contaminant by exhaust ventilation.

Wear personal protective equipment such as respirator, protective clothing, gloves as

appropriate.

Wiping off flammable liquid spills or leakage: Beware of fire Friction from wiping off flammable liquid (such as petrol, acetone, etc.) spills or leakage

using a piece of cloth may generate static electricity. Spark forms when discharge occurs. The spark ignites the flammable vapor in the vicinity, and consequently the flammable liquid will be on fire.

Safe practices

No source of ignition is allowed in the vicinity of any place where flammable substances are stored or handled !

Increase the ventilation in the place to avoid accumulation of flammable vapour whenever any flammable liquid spill or leakage is found.

Remove the flammable liquid spill or leakage by absorbent materials to avoid generation of static electricity due to friction.

Wear personal protective equipment such as respirator, protective clothing, gloves as appropriate.

Dissolving caustic soda: Beware of splashes of superheated corrosive liquid Caustic soda (sodium hydroxide) pellets dissolve in water to form alkaline

solution and evolve heat. The process may cause localized heating and even superheating. When the solution is disturbed such as lifting the container, bubbles form spontaneously and rush out, leading to splashing of the hot corrosive liquid

Safe practices

l Don't add water to caustic soda pellets or strong alkaline solutions! l The correct method is to add caustic soda or other strong alkaline

solutions slowly to water. Constantly stir the solution to prevent localized heating, and to help bubble formation in avoiding superheating. Cool the outside of the container by cold water or ice if necessary. l Wear personal protective equipment such as gloves, eye protection as appropriate

Diluting acids: Beware of splashes of corrosive liquid and emission of acid fumes In general, diluting acids (such as hydrochloric acid, nitric acid, sulphuric acid, etc.) is an

exothermic process. During dilution the acid solution may experience localized heating and evolves gas bubbles and acid fumes, or even be superheated. Bubbling can easily lead to splashing of hot corrosive liquid.

Safe practices

Don't add water to concentrated acid !

The correct method of dilution is to add acid slowly to water and constantly stir the solution. Cool the outside of the container by cold water or ice if necessary.

Operate under local exhaust ventilation to vent away acid fumes.

Wear personal protective equipment such as gloves, eye protection as appropriate.

Lab Safety Rules

Conduct yourself in a responsible manner at all times in the laboratory.

Follow all written and verbal instructions carefully. If you do not understand a direction or part of a procedure, ASK YOUR SUPERVISOR BEFORE PROCEEDING WITH THE ACTIVITY.

Never work alone in the laboratory. No student may work in the science classroom without the presence of the supervisor.

When first entering a science room, do not touch any equipment, chemicals, or other materials in the laboratory area until you are instructed to do so.

Perform only those experiments authorized by your supervisor. Carefully follow all instructions, both written and oral. Unauthorized experiments are not allowed.

Do not eat food, drink beverages, or chew gum in the laboratory. Do not use laboratory glassware as containers for food or beverages.

Be prepared for your work in the laboratory. Read all procedures thoroughly before entering the laboratory. Never fool around in the laboratory. Horseplay, practical jokes, and pranks are dangerous and prohibited.

Always work in a well-ventilated area.

Observe good housekeeping practices. Work areas should be kept clean and tidy at all times.

Be alert and proceed with caution at all times in the laboratory. Notify the supervisor immediately of any unsafe conditions you observe.

Dispose of all chemical waste properly. Never mix chemicals in sink drains. Sinks are to be used only for water. Check with your supervisor for disposal of chemicals and solutions.

Labels and equipment instructions must be read carefully before use. Set up and use the equipment as directed by your supervisor.

Keep hands away from face, eyes, mouth, and body while using chemicals or lab equipment. Wash your hands with soap and water after performing all experiments.

Experiments must be personally monitored at all times. Do not wander around the room, distract other students, startle other students or interfere with the laboratory experiments of others.

Know the locations and operating procedures of all safety equipment including: first aid kit(s), and fire extinguisher. Know where the fire alarm and the exits are located.

Know what to do if there is a fire drill during a laboratory period; containers must be closed, and any electrical equipment turned off.

Any time chemicals, heat, or glassware are used, students will wear safety goggles. NO EXCEPTIONS TO THIS RULE!

Contact lenses may be not be worn in the laboratory.

Dress properly during a laboratory activity. Long hair, dangling jewelry, and loose or baggy clothing are a hazard in the laboratory. Long hair must be tied back, and dangling jewelry and baggy clothing must be secured. Shoes must completely cover the foot. No sandals allowed on lab days.

A lab coat or smock should be worn during laboratory experiments.

Report any accident (spill, breakage, etc.) or injury (cut, burn, etc.) to the teacher immediately, no matter how trivial it seems. Do not panic.

If you or your lab partner is hurt, immediately (and loudly) yell out the supervisor's name to get the teacher's attention. Do not panic.

If a chemical should splash in your eye(s) or on your skin, immediately flush with running water for at least 20 minutes. Immediately (and loudly) yell out the teacher's name to get the supervisor's attention.

All chemicals in the laboratory are to be considered dangerous. Avoid handling chemicals with fingers. Always use a tweezers. When making an observation, keep at least 1 foot away from the specimen. Do not taste, or smell any chemicals.

Check the label on all chemical bottles twice before removing any of the contents. Take only as much chemical as you need.

Never return unused chemicals to their original container.

Never remove chemicals or other materials from the laboratory area.

Never handle broken glass with your bare hands. Use a brush and dustpan to clean up broken glass. Place broken glass in the designated glass disposal container.

Examine glassware before each use. Never use chipped, cracked, or dirty glassware.

If you do not understand how to use a piece of equipment, ASK THE supervisor FOR HELP!

Do not immerse hot glassware in cold water. The glassware may shatter.

Do not operate a hot plate by yourself. Take care that hair, clothing, and hands are a safe distance from the hot plate at all times. Use of hot plate is only allowed in the presence of the teacher. Heated glassware remain very hot for a long time. They should be set aside in a designated place to cool, and picked up with caution. Use tongs or heat protective gloves if necessary.

Never look into a container that is being heated.

Do not place hot apparatus directly on the laboratory desk. Always use an insulated pad. Allow plenty of time for hot apparatus to cool before touching it.

How to identify color chemical table?

Here's a list of chemical elements ordered by increasing atomic number. The names and element symbols are provided.

1 - H - Hydrogen 26 - Fe - Iron 51 - Sb - Antimony 76 - Os - Osmium 101 - Md - Mendelevium

2 - He - Helium 27 - Co - Cobalt 52 - Te - Tellurium 77 - Ir - Iridium 102 - No - Nobelium

3 - Li - Lithium 28 - Ni - Nickel 53 - I - Iodine 78 - Pt - Platinum 103 - Lr - Lawrencium

4 - Be - Beryllium 29 - Cu - Copper 54 - Xe - Xenon 79 - Au - Gold 104 - Rf - Rutherfordium

5 - B - Boron 30 - Zn - Zinc 55 - Cs - Cesium 80 - Hg - Mercury 105 - Db - Dubnium

6 - C - Carbon 31 - Ga - Gallium 56 - Ba - Barium 81 - Tl - Thallium 106 - Sg - Seaborgium

7 - N - Nitrogen 32 - Ge - Germanium 57 - La - Lanthanum 82 - Pb - Lead 107 - Bh - Bohrium

8 - O - Oxygen 33 - As - Arsenic 58 - Ce - Cerium 83 - Bi - Bismuth 108 - Hs - Hassium

9 - F - Fluorine 34 - Se - Selenium 59 - Pr - Praseodymium 84 - Po - Polonium 109 - Mt - Meitnerium

10 - Ne - Neon 35 - Br - Bromine 60 - Nd - Neodymium 85 - At - Astatine 110 - Ds - Darmstadtium

11 - Na - Sodium 36 - Kr - Krypton 61 - Pm - Promethium 86 - Rn - Radon 111 - Rg - Roentgenium

12 - Mg - Magnesium 37 - Rb - Rubidium 62 - Sm - Samarium 87 - Fr - Francium 112 - Cn - Copernicium

13 - Al - Aluminum, Aluminium 38 - Sr - Strontium 63 - Eu - Europium 88 - Ra - Radium

113 - Uut - Ununtrium

14 - Si - Silicon 39 - Y - Yttrium 64 - Gd - Gadolinium 89 - Ac - Actinium 114 - Fl - Flerovium

15 - P - Phosphorus 40 - Zr - Zirconium 65 - Tb - Terbium 90 - Th - Thorium 115 - Uup - Ununpentium

16 - S - Sulfur 41 - Nb - Niobium 66 - Dy - Dysprosium 91 - Pa - Protactinium 116 - Lv - Livermorium

17 - Cl - Chlorine 42 - Mo - Molybdenum 67 - Ho - Holmium 92 - U - Uranium 117 - Uus - Ununseptium

18 - Ar - Argon 43 - Tc - Technetium 68 - Er - Erbium 93 - Np - Neptunium 118 - Uuo - Ununoctium

19 - K - Potassium 44 - Ru - Ruthenium 69 - Tm - Thulium 94 - Pu - Plutonium

20 - Ca - Calcium 45 - Rh - Rhodium 70 - Yb - Ytterbium 95 - Am - Americium

21 - Sc - Scandium 46 - Pd - Palladium 71 - Lu - Lutetium 96 - Cm - Curium

22 - Ti - Titanium 47 - Ag - Silver 72 - Hf - Hafnium 97 - Bk - Berkelium

23 - V - Vanadium 48 - Cd - Cadmium 73 - Ta - Tantalum 98 - Cf - Californium

24 - Cr - Chromium 49 - In - Indium 74 - W - Tungsten 99 - Es - Einsteinium

25 - Mn - Manganese 50 - Sn - Tin 75 - Re - Rhenium 100 - Fm - Fermium

Thank You