OXIDIZING MATERIALS

The dangerous of chemical substenses are classified into 6. toxic,

corrosive, flammable, explossive, harmful, and oxidizing. It especially will

explain about oxidizing. We will discuss about definition, properties, example,

materials handling, emergency handling, storage, waste disposal, safety

equipment, and housekeeping oxidizing materials. It is important for us to know

the material’s label because it is very usefull for us as chemical engineering who

work in laboratory. Besides that, we must be able recognize properties of

oxidizing material, so that we can reduce the risk of their bad effect.

Pic 1. Oxidizing Label

I. Definition of Oxidizing Materials

Oxidizing materials are chemicals that can decompose readily to produce

oxygen or an oxidizing substance at room temperature or with slight heating and

promote combustion. The usual source for burning is air. Oxidizing materials can

supply combustible substances with oxygen and support a fire even when air is

not present. Oxidizing materials can speed up the development of a fire and make

it burn more intensely, cause substances to burn rapidly that do not normally burn

readily in air and cause combustible materials to burn spontaneously without the

presence of an ignition source such as a spark of flame. Some oxidizing materials

are themselves combustible.An oxidizing agent is the element or compound in an

oxidation-reduction (redox) reaction that accepts an electronfrom another species.

II. Properties of Oxidizing Materials

Oxidizing materials have properties that can produce oxygen (which is one

of the requirements the fire: oxygen, fuel, heat). This material can provide oxygen

in a reaction even though there is no air. Besides that, oxidizing agents can react

with reducing agents to generate heat and products that may be gaseous (causing

pressurization of closed containers). Explosive mixtures of oxidizing agents with

reducing agents often persist unchanged for long periods if initiation is prevented.

Actual reactivity varies greatly with the identity of the organic compound.

Oxidizing agents can react violently with active metals, cyanides, esters, and

thiocyanates.

III. Examples of Oxidizing Material

Bromine

Chromic acid

Sodium perchlorate

Hydrogen peroxide

Ammonium permanganate

Barium peroxide

Potassium peroxide

Calcium chlorate

Fluorine

Magnesium peroxide

etc

IV. Storage of Oxidizing Materials

Storage requirements oxidizing Materials are:

a. Cold temperatures

Oxidizers should be stored in a cool and dry location.For these

oxidizers, ensure that the storage temperature is kept at least 14°C (25°F)

below their decomposition temperature. Avoid storing any oxidizer at

temperatures above 49°C (120°F).

b. Storage Area

Oxidizing materials must be stored in fire resistant building.

Storage areas may need alarms that provide a warning when storage

temperatures are higher or lower than required.Walls, floors, shelving, and

fittings in storage areas should be constructed of non combustible

materials. Wood impregnated with a fire retardant material is not fully

protected against the increased fire hazard caused by contact with

oxidizers. Protect metal construction materials against corrosion by

painting them with a compatible coating.

Store oxidizer containers at a convenient height for handling,

below eye level if possible, to reduce the risk of dropping containers.

Avoid overcrowding in storage areas. Do not store containers in out-of-

the-way locations where they could be forgotten.

c. Keep the oxidizing material out of fuel, combustible materials, and

materials that have a low flame point.

Segregate oxidizers from all other chemicals in the laboratory.

Store oxidizing materials separately away from processing and handling

areas and away from other materials. Separate storage can reduce the risk

of personal injury and damage in case of fires, spills or leaks. If totally

separate storage is not possible, store oxidizing materials away from

incompatible materials especially organic or other oxidizable materials

(sometimes called reducing materials or reducing agents).

Some oxidizing materials are incompatible or may react with each

other, sometimes violently. Do not store them beside each other. Check the

reactivity data and storage requirements sections of the MSDS for details

about what materials are incompatible with a specific oxidizer.

d. Special ventilation

The properly working vent will prevent the build-up of pressure

inside containers. The normal build-up of pressure could rupture an

unvented container. Check vent caps regularly to ensure that they are

working properly. Keep vented containers in the upright position. Never

stack vented containers on top of each other.

e. Label Storage

Containers and storage areas must be labeled to include the name

of the material, the level of danger, date received and used. For example,

red for flammable materials, oxidizing materials yellow, blue for toxic

materials, white to corrosive materials, and green for low danger materials.

For oxidizing materials requiring temperature control, the

recommended storage temperature range should be plainly marked on the

container. It is also a good practice to mark the date that the container was

received and the date it was first opened.

f. Container

Before storing, inspect all incoming containers to ensure that they

are undamaged. Repackaging can be very dangerous especially when

using contaminated or incompatible containers. Protect containers against

banging or other physical damage when storing, transferring or using

them. Do not use wooden pallets or other combustible pallets for storing

containers of oxidizing materials.

Normally keep containers tightly closed when storing unless the

supplier's instructions state otherwise. This helps to avoid contamination

of the material or evaporation of solvents used to dilute oxidizers, such as

organic peroxides, to safer concentrations.Keep only the smallest amounts

possible (not more than one day's supply) of oxidizers in work

areas.Empty drums, bottles, bags, sacks and other "oxidizing agent"

containers usually have hazardous oxidizing residues inside them

V. Hazard of Oxidizing Materials

General Hazards of Oxidizers

As will be discussed in more detail, oxidizers pose a serious fire hazard

because they:

Intensify combustion

Widen the flammable range of flammable gases and liquids

Lower the flashpoints and ignition temperatures of combustible materials

so these materials ignite more readily.

Oxidizers cause or contribute to the combustion of other materials by

providing oxygen to support the combustion process. Combustion requires four

factors to occur:

• A combustible (oxidizable) material

• An ignition source

• Oxygen

• An ongoing reaction that generates free radicals

The health hazard with oxidizing gases is inhalation. With the exception of

oxygen, oxidizing gases are very toxic and cause potentially lethal chemical

pulmonary edema even with brief exposures.

VI. Handling Oxidizing Materials

The Rules of Handling Oxidizing Materials

1. Make sure that all areas where oxidizing materials are used are free of

combustible and other incompatible materials.

2. Do not allow tobacco smoking or any other ignition sources around oxidizing

materials.

3. Ensure that temperatures in these areas do not become high enough to cause

rapid decomposition of the materials. For example, hydrogen peroxide

decomposes almost twice as fast for every 5.6°C (10°F) temperature rise.

4. In laboratories, do not use corks, rubber stoppers or stopcock grease to seal

containers of strong oxidizing materials.

5. Use fibreglass heating mantles or sand baths instead of oil baths to heat

reaction vessels containing significant amounts of oxidizing materials.

6. Follow the chemical producer's instructions regarding the handling of

oxidizing agents.

Spill Responses

1. Anticipate spills by having the appropriate clean up equipment on hand. This

should occur prior to the use of any oxidizing materials. Spill control

materials for oxidizers are designed to be inert and will not react with the

reagent.

2. Never use paper towels or other inappropriate materials which are

combustible.

3. The waste materials generated during spill cleanup may pose a flammability

risk and should not remain in the laboratory overnight unless it is stored in an

appropriate container.

4. Do not attempt to handle a large spill of oxidizing materials.

Decontamination Procedures

1. Wash hands and arms with soap and water immediately after handling any

chemical.

2. Clean work areas carefully when done.

3. Dispose of contaminated material in the hazardous waste storage container.

4. Do not dispose of waste with incompatible material.

5. Paper towels or other similar material may pose a fire risk when

contaminated. Proceed with caution when working with oxidizers around

other organic material (paper, wood, cloth).

Personal Cleanliness Procedures

Personal cleanliness helps protect you when you are working with oxidizers:

1. Wash hands before eating, drinking, smoking or going to the toilet.

2. Remove contaminated clothing and leather shoes or boots since they can be a

severe fire hazard.

3. Wash contaminated items immediately and thoroughly in water before re-

wearing or discarding.

4. Do not wear or carry contaminated clothing or footwear into areas having

ignition sources or where smoking is allowed.

5. Store food and tobacco products in uncontaminated areas.

6. Avoid touching yourself (e.g., scratching your nose or rubbing your eyes) with

contaminated hands.

7. Wash thoroughly at the end of the workday even though you have done

everything mentioned before.

VII. Waste Disposal Requirements

1. Add a reducing solution (hypo, bisulfite or ferosulfat plus H2SO4). Let the

reaction is complete and neutralize with NaOH or HCl. Discard the water.

2. We should know about dispensing and using oxidizing liquids and solids

3. Be very careful when dispensing oxidizers from storage containers into

other containers.

4. Avoid spilling fchemic and contaminating your skin or clothing. Spills from

open, unstable or, breakable containers during material transfer have caused

serious accidents.

5. Dispense from only one container at a time. Finish all the dispensing of one

material before starting to dispense another. Dispense the smallest amount

possible, preferably only enough for immediate use.

6. Keep containers closed after dispensing to reduce the risk of contaminating

their contents.

7. Never dispose of oxidizers in ordinary garbage or down sinks or drains that

connect to sanitary or storm sewers.

8. Dispose of them according to the supplier's directions, or through hazardous

waste collection and disposal companies

VIII. Safety Equipments

8.1 Self Safety Equipments

a. Eye Protection (Googles/ safety glasses)

Eye protection must be worn at all times when handling oxidizing

materials.

Pic 2. Googles

Ordinary glasses do not provide adequate protection. (Contrary to

popular opinion these glasses cannot pass the rigorous test for industrial

safety glasses). Adequate safety glasses must meet the requirements of the

Practice for Occupational and Educational Eye and Face Protection and

must be equipped with side shields. Safety glasses with side shields do not

provide adequate protection from splashes; therefore, when the potential

for splash hazard exists other eye protection and/or face protection must be

worn. Always wear eye protection when working with oxidizers. Avoid

ordinary safety glasses. Use chemical safety goggles instead.

b. Hand Protection

Pic 3. Gloves

Gloves should be worn when handling oxidizing materials.

Disposable gloves provide adequate protection against accidental hand

contact with small quantities of most laboratory chemicals. Gloves are

made of thick rubber and fireproof.

c. Face Protection

Pic 4. Face Protection (safety shielding)

Safety shielding is required any time there is a risk of explosion, splash

hazard or a highly exothermic reaction. Portable shields, which provide

protection to all laboratory occupants are acceptable.Safety shielding

ismade of transparent plastic sheet that can cover all the faces that can

protect all face from splashes or spray liquids or hazardous dust.

d. Body Protection (Lab coat)

Pic 5. Laboratory Coat

Lab coats must be used in the laboratory on chemical procces including

oxidizing materials. characteristics of a good lab coats to be used in this case

is to have long sleeves and it is made of thick fabric.

e. Respiratory protections

Pic 6. Chemical Respiratory

Avoid Breathing Dusts, Mists or Vapours. If respirators must be used for

breathing protection, develop and follow a written respiratory protection program,

as described in the Respirator Selection question-and-answer document.Sorbents

in respirator cartridges or canisters must be compatible with the chemical they are

supposed to protect against. For example, oxidizable sorbents, such as activated

charcoal, may not be acceptable if high airborne concentrations of strong

oxidizers are present. A hazardous reaction might occur.

8.2 Emergency Handling Oxidizing Safety Equipment

a. Eye wash

Pic 7. Eye wash

Where the eyes or body of any person may be exposed to oxidizing

materials, suitable facilities for quick drenching or flushing of the eyes and

body shall be provided within the work area for immediate emergency use.

Bottle type eyewash stations are not acceptable.

b.Safety shower

A safety or drench shower should be available in a nearby location

where the oxidizing materials are used. This equipment is prepared for some

accident. Actually, if there are person is burned by the fire from oxidizing

materials, we can use safety shower to get the first handling.

Pic 8. Safety Shower

8.3 Oxidizing Practices Safety Equipment

a. Fume hood

Pic 9. Fume hood

The use of certain concentrations of perchloric acid must be performed in

a fume hood equipped with wash down facilities. Contact the Office of

Environmental Health and Radiation Safety for fume hood requirements.

b. Special ventilation

Pic 10. Special Ventilation

Well-designed and well-maintained ventilation systems remove airborne

oxidizing materials from the workplace and reduce their hazards. The amount and

type of ventilation needed depends on such things as the type of job, the kind and

amount of materials used, and the size and layout of the work area. An assessment

of the particular ways a workplace stores, handles, uses and disposes of its

oxidizing materials is the best way to find out if existing ventilation controls (and

other hazard control methods) are adequate.

Organic materials, such as wood, should not be used in ventilation systems

for oxidizing materials. Systems should be free of ignition sources and separate

from other systems that might be exhausting incompatible substances. The system

may also need to be corrosion-resistant if the material is corrosive. Air cleaning

devices such as dust collectors should be made from non-combustible materials.

Source :

www.hc-sc.gc.ca/ewh-semt/occup-travail/whmis-simdut/oxidizing-comburantes-

eng.php

www.ccohs.ca/oshanswers/chemicals/oxidizing/oxiziding_hazards.html

www.brandeis.edu/ehs/labs/oxidizers.html

www.ihsa.ca/whmis_review/oxidizing_materials.html

www.ccohs.ca/oshanswers/legisl/whmis_classifi.html

Conclution

Oxidizing materials are materials that spontaneously evolve oxygen at

room temperature or with slight heating or promote combustion.

Storage requirements of oxidizing materials are cold temperatures, there

Circulation Eve, Fire-resistant building, kept out of fuel, combustible

materials, materials that have a low flame poin and special ventilation.

Safety Equipmentsof oxidizing materials are eye protection,eyewash, fume

hood,glove (dry) box, gloves, hazard assessment, EHRS Notification,

protective apparel, safety shielding, safety shower, speciall ventilation,

signs and labels, vacuum protection and waste disposal.

To handle emergencies involving oxidizing materials, In the event of a

spill or adverse reaction notify lab personnel immediately that an incident

has occurred. Do not attempt to handle a large spill/reaction/fire, or one in

which you are not trained or equipped for. Turn off all ignition sources if

this can be done safely; vacate the area and call for assistance.