chemical safety

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Chemical Safety

Objective : Learning, Awareness & Actions


Classification of Hazardous Chemicals


Corrosive• A corrosive substance is one that will destroy

and damage other substances with which it comes into contact. It may attack a great variety of materials including metals.

• Common corrosive chemicals

• Acids: • Sulphuric Acid• Hydrochloric Acid

• Bases:• Sodium Hydroxide• Calcium Hydroxide


Dangerous for the environment• Chemicals enter into air as emissions and water

as effluent. Industrial and motor vehicle emissions of nitrogen and sulphur oxides cause acid rain, which poisons fish and other aquatic organisms in rivers and lakes and affects the ability of soil to support plants. Carbon dioxide causes the greenhouse effect and climate change.

• Water Treatment Plant Effluents.• Emissions from Stack.• Chemical Effluents from main plant.


Explosive• Explosive, is a reactive substance that contains a

great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure.

• chemical energy, such as nitro-glycerine or grain

dust.• pressurized gas, such as a gas cylinder or

aerosol can.• Nuclear energy, such as in the fissile isotopes

uranium-235 and plutonium-239


Toxic• Any chemical or mixture having capability to

harm the environment, living being’s and to human health by any mode of exposure (if inhaled, swallowed, or absorbed through the skin) is termed as Toxic chemical.

• Toxic Chemicals:• Ammonia• Chlorine• Hydrochloric Acid• Hydrazine


Oxidizing

• Oxidizing agent is a substance that is not necessarily combustible, but may, generally by yielding oxygen, cause or contribute to the combustion of other material.

• Common oxidizing agents:• Oxygen• Sulphuric Acid• Hypochlorite• Chlorine


Harmful• Many materials or substances used or created at

work could harm your health. These substances could be dusts, gases or fumes that you breathe in, or liquids, gels or powders that come into contact with your eyes or skin. There could also be harmful micro-organisms present that can cause infection, an allergic reaction or are toxic. Harmful substances can be present in anything from paints and cleaners to flour dust, solder fume, blood or waste.

• Laboratory Chemicals• Bulk Chemicals


Extremely Flammable• A High Flammable Liquid is a liquid with a flash

point below 32 °C (The flash point of a liquid is the lowest temperature at which the liquid gives off vapour in sufficient concentration to form a combustible mixture with air near the surface of the liquid.) The flash points of some common laboratory solvents are:

• Ethanol +12 °C• Toluene +4 °C• Acetone -19 °C• Diethyl ether -45 °C


Bulk Chemical Used in Power Plant• Sulphuric Acid – H2SO4• Hydrochloric Acid - HCl• Sodium Hydroxide - NaOH• Ammonia – NH3• Hydrazine – N2H4• Ferric Chloride – FeCl3• Polyelectrolyte – (C3H4O2)n• Hydrated Lime – Ca(OH)2• Tri Sodium Phosphate – Na3PO4• Chlorine - Cl• Hydrogen – H2


Sulphuric Acid• Properties:• Sulphuric acid is a highly corrosive strong

mineral acid. It is a colourless to slightly yellow viscous liquid that is soluble in water at all concentrations.

• Uses in Power Plant:• In Treatment of Condenser cooling water and

Laboratory purpose.


Sulphuric Acid• Health Hazards of Sulphuric Acid:• Concentrated sulphuric acid is extremely corrosive and can cause

serious burns when not handled properly. This dangerous chemical is capable of corroding skin, paper, metals, and even stone in some cases. If sulphuric acid makes direct contact with the eyes, it can cause permanent blindness. If ingested, this chemical may cause internal burns, irreversible organ damage, and possibly death.


Hydrochloric Acid• Properties:• Hydrochloric acid is a clear, colourless,

highly pungent solution pungent solution of hydrogen chloride (HCl) in water. It is a highly corrosive, strong mineral acid with many industrial uses.

• Uses in Power Plant:• In regeneration of Mixed Bed and CPU and

Laboratory purpose.


Hydrochloric Acid• Health Hazards of Hydrochloric Acid:• Hydrochloric acid is a hazardous liquid which must be used with care. The

acid itself is corrosive, and concentrated forms release acidic mists that are also dangerous. If the acid or mist come into contact with the skin, eyes, or internal organs, the damage can be irreversible or even fatal in severe cases.


Sulphuric Acid & Hydrochloric Acid Safety• It is recommended that you wear the following protective equipment

when using Sulphuric acid and hydrochloric acid of any concentration:• Vapour respirator, • Long Rubber gloves• Boots• Full suit• Face shield• Chemical Safety goggles


Care for H2SO4 / HCl Exposure

• Exposure to H2SO4/HCl can occur as skin/bodily contact, ingestion, or inhalation of vapours. Each type of exposure can pose serious hazards to your health and should be managed immediately and appropriately by a medical professional to minimize damage and health risks.

• Skin Contact – If H2SO4/HCl comes into contact with your skin, immediately flush the affected area gently with lukewarm water for at least 30 uninterrupted minutes. Seek medical attention immediately.

• Eye Contact – If H2SO4/HCl gets into your eyes, immediately flush the eye(s) with water for at least 30 minutes. Seek medical attention immediately.

• Ingestion – If you ingest H2SO4/HCl, rinse your mouth immediately with water. Do not induce vomiting. Continually rinse your mouth with water and seek medical attention as soon as possible.

• Inhalation – If you inhale H2SO4/HCl aerosols, seek fresh air and medical attention immediately.


Eye washer cum Safety shower


Hydrazine• Properties:• Hydrazine is an inorganic compound. It

is a colourless flammable liquid with an ammonia-like odour. Hydrazine is highly toxic and dangerously unstable unless handled in solution.

• Uses in Power Plant:• In the treatment of feed water system to

protect boiler and pre-boiler equipment's from oxygen. Used as an oxygen scavenger.


Hydrazine• Health Hazards of Hydrazine:• Hydrazine is highly toxic and

dangerously unstable, especially in the anhydrous form. Symptoms of acute (short-term) exposure to high levels of hydrazine may include:

• irritation of the eyes. • Nose and throat. • Dizziness.• Headache. • Nausea.• Coma in humans.


Sodium Hydroxide• Properties:• Sodium hydroxide (NaOH), also known

as lye and caustic soda is an inorganic compound. It is a white solid and highly caustic metallic base and alkali of sodium which is available in pellets, flakes, granules, and as prepared solutions at a number of different concentrations.

• Uses in Power Plant:• In regeneration of Mixed Bed and CPU

and Laboratory purpose.


Sodium Hydroxide• Health Hazards of Sodium Hydroxide:• Contact can severely irritate and burn the skin and eyes with possible

permanent eye damage, causing blindness. Contact can irritate mouth, nose and throat. Inhaling can irritate the lungs causing coughing and shortness of breath.


Sodium Hydroxide Safety


Ammonia• Properties:• Ammonia is a colourless gas with a

characteristic pungent smell. Ammonia is extremely soluble in water and is frequently used as a water solution called aqua ammonia.

• Uses in Power Plant:• In the treatment of feed water system to

protect boiler and pre-boiler equipment's from corrosion.


Ammonia• Health Hazards of Ammonia:• Anhydrous ammonia primarily affects three areas of the body 1.

Eyes, 2. Lungs and 3. Skin. Everything from mild irritation to destruction of the eye can occur depending on whether a spray or gas is involved. Ammonia penetrates the eye more rapidly than other alkalis. In the lungs, liquid anhydrous ammonia causes destruction of delicate respiratory tissue.


Ammonia & Hydrazine Safety• It is recommended that you wear the following protective equipment

when using Ammonia and hydrazine of any concentration:• Vapour respirator, • Rubber gloves• Boots• Full suit• Face shield• Chemical Safety goggles


• Properties:• Ferric chloride is the coagulant of choice

for many industrial and sanitary wastewater treatment applications, due to its high efficiency, effectiveness in clarification. The chemical leaves slight residual colour, and offers very good turbidity removal.

• Uses in Power Plant:• In the pre-treatment of raw water and

waste water as a coagulant.

Ferric Chloride


• Health Hazards of Ferric chloride:• Iron(III) chloride is toxic, highly corrosive and acidic. The anhydrous

material is a powerful dehydrating agent. Although reports of poisoning in humans are rare, ingestion of ferric chloride can result in serious morbidity and mortality. Inappropriate labelling and storage lead to accidental swallowing or misdiagnosis

Ferric Chloride


Polyelectrolyte• Properties:• Polyelectrolytes are polymers whose repeating

units bear an electrolyte group. Poly cations and poly anions are polyelectrolytes. These groups dissociate in aqueous solutions (water), making the polymers charged. Polyelectrolyte properties are thus similar to both electrolytes (salts) and polymers (high molecular weight compounds) and are sometimes called poly salts.

• Uses in Power Plant:• In the pre-treatment of raw water and waste

water as a flocculent.


Polyelectrolyte• Health Hazards of polyelectrolyte:• This product is not expected to be a sensitizer. Acute: A review of

available data does not identify any symptoms from exposure not previously mentioned. Chronic: Frequent or prolonged contact with product may defat and dry the skin, leading to discomfort and dermatitis.


Hydrated Lime• Properties:• Calcium hydroxide, traditionally called slaked

lime, It is a colourless crystal or white powder and is obtained when calcium oxide (called lime or quicklime) is mixed, or "slaked" with water. It has many names including hydrated lime, caustic lime, builders' lime, slack lime, cal or pickling lime.

• Uses in Power Plant:• In the pre-treatment of raw water and waste

water.


Hydrated Lime• Health Hazards of Hydrated Lime:• Unprotected exposure to Ca(OH)2 can pose health risks, so it should

be limited. It can cause severe skin irritation, chemical burns, blindness, or lung damage.


Tri Sodium Phosphate• Properties:• Tri sodium phosphate (TSP) is

the inorganic compound with the chemical formula Na3PO4. It is a white, granular or crystalline solid, highly soluble in water producing an alkaline solution. TSPs are used as cleaning agent, lubricant, food additive, stain remover and degreaser.

• Uses in Power Plant:• In the treatment of Boiler drum water.


Tri Sodium Phosphate• Health Hazards of Tri Sodium Phosphate:• Acute Potential Health Effects: Skin: Causes skin irritation with

possible burning pain and corrosive damage. Eyes: Causes eye irritation. This substance may cause eye burns. Inhalation: May be harmful if inhaled. Inhalation of dust may cause respiratory tract and mucous membrane irritation with coughing, sneezing, choking, difficulty breathing, and pulmonary edema.


Chlorine• Properties:• Chlorine is a toxic gas that irritates the

respiratory system. Because it is heavier than air, it tends to accumulate at the bottom of poorly ventilated spaces. Chlorine gas is a strong oxidizer, which may react with flammable materials. Chlorine is used as a disinfectants in the treatment of drinking water.This is a yellow-green gas that has a distinctive strong odour.

• Uses in Power Plant:• In the pre treatment of raw water, waste

water and cooling tower.


Chlorine• Health Hazards of Chlorine:• Chlorine is detectable with measuring devices in concentrations

of as low as 0.2 parts per million (ppm), and by smell at 3 ppm. Coughing and vomiting may occur at 30 ppm and lung damage at 60 ppm. About 1000 ppm can be fatal after a few deep breaths of the gas.


Guidelines of safe handling of chlorine• Chlorine need not be a serious hazard if the people working with it are properly

trained in its handling.• The following are the guidelines for assuring the safe handling of chlorine. • Provide proper instruction and supervision to workers responsible for chlorine

equipment.• Provide proper and approved self-contained breathing apparatus in areas

where chlorine is stored or used. • Keep all breathing apparatus stored outside the chlorine area.


Guidelines of safe handling of chlorine• Prepare escape plans from areas where there might be a chlorine

emission. Remember to move uphill and upwind.• Never store combustible or flammable materials near chlorine

containers.• Never apply heat directly to a chlorine• Never attempt to weld an “empty” chlorine pipe line without purging it

with air first.


Guidelines of safe handling of chlorine• Install safety showers and eye wash stations near chlorine equipment. • If there is a leak, at least two persons should make the repairs. • Never spray water on leaking containers; it can make the leak worse.• When entering an equipment area, take shallow breaths until you are

sure that there is not a chlorine gas leak.• Always keep ready Chlorine Leak Absorption System.


Chlorine First AidInhalation Remove victim from contaminated area. Keep victim warm in a reclined position with head and shoulders

elevated. Give artificial respiration, if necessary. Give oxygen as soon as possible. Call emergency personnel or a physician immediately.

Skin Contact Shower victim, removing all contaminated clothing. Wash affected area with soap and water.

Eye Contact Irrigate eyes with water for 15 minutes, holding eye lids wide apart. Call emergency personnel or a physician immediately. Irrigate for second 15-minute period if emergency personnel or

physician is not immediately available


Hydrogen• Properties:• hydrogen is a colourless, odourless,

non-metallic, tasteless, non-toxic, highly combustible diatomic gas with the molecular formula H2.

• Uses in Power Plant:• In the cooling of generator rotor due to

its specific heat capacity being considerably higher than any other gas.


Hydrogen• Health Hazards of Hydrogen:• Hydrogen poses a number of hazards to human safety, from potential

detonations and fires when mixed with air to being asphyxiate in its pure, oxygen-free form. Hydrogen gas leaking into external air may spontaneously ignite. Moreover, hydrogen fire, while being extremely hot, is almost invisible, and thus can lead to accidental burns.


Presentation byRama Chandra Reddy Butcha

Group Head – Chemical & EnvironmentTata Power Company Limited

chemical safety

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