chemical safety

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Occupational Health & Hygiene

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A discipline devoted to recognising, evaluating and controlling workplace hazards that causes illnesses depending on the nature of the contributing factors and the resultant effects.

Industrial Hygiene

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ChemicalPhysicalBiologicalErgonomics Radiation

Workplace hazards

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Chemical Hazards

Paints, Solvent,Thinners, Acids, Alkalies

Chemical hazards at work place arise: Inhalation or Absorption through the skin Of toxic chemicals.Toxic chemicals are those chemicals, which on entering the body, affect the function of different systems of the body.

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Types of Chemical Hazards1.Dust:

Solid particles generated by handling, crushing, grinding, impacting, detonation and breaking apart by heating organic or inorganic materials.

Rock, Ore, Metal, Coal, Wood and Grain.

Respirable Dust: Particles < 10 microns can enter into the lungs.

Non-respirable Dust: Particles > 10 microns Impact and get struck in the upper respiratory tract and do not enter the lungs.

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2. Fumes:Fumes are volatised solids that condense when they contact air. Fumes are very small, solid particles created when hot vapour reacts with the air to form an oxide. Fumes are often associated with welding operations.

Types of Chemical Hazards

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3. Mists / Aerosols:Mists / Aerosols are suspended liquid droplets created when vapour condenses back to a liquid, or during splashing and atomising. Acid mists from electroplatingOil mist during cutting / grinding spray mist from spray finishing

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4.Fibers:Fibers are solid particles having a slender, elongated shape several times as great as their diameter. Examples of fibers include asbestos, Fiberglass and fibrous talc. Fibers are commonly found in construction, mining, friction product manufacturing and fabrication.

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5. Gases:Gases are formless fluids that expand to occupy the space in where they are confined.

Gases are commonly formed by arc-welding and internal combustion engine exhausts.

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6.Vapour:Vapours are volatile forms of substance that are normally in the solid or liquid state at room temperature. Organic solvents with low boiling points which form vapours readily at room temperature.

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Acute exposures and effects may result due to accidental massive leakage.

Chronic effects are due to repeated exposures to concentrations exceeding the permissible limits (TLVs), but well below the levels needed for acute effects.

Acute and Chronic Effects

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If man is exposed to different levels of airborne concentrations of a toxic substance, up to a certain level, the body does not suffer from any effect.

When concentration exceeds this level, typical symptoms start manifesting in a few of the exposed individuals. This level beyond which symptoms start appearing, is called the Threshold Limit Value (TLV). The TLVs are expressed as parts per million (ppm) or milligram per cubic metre (mg/m3).

Threshold Limit Values (TLVs)

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At any work place the concentration of the toxic chemicals fluctuating during the shift depending on the process conditions.

The exposure of the worker will be the average of the concentrations recorded during the shift. This average concentration is called as Time Weighted Average Concentration.

Time Weighted Average Concentration:

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The time weighted average exposure concept accepts fluctuations in the concentrations. So ‘Short Term Exposure Limit (STEL)’ has also been prescribed.

The STEL values may be 1.25 to 8 times the corresponding TLV’s for different substances.

Short Term Exposure Limits (STEL)

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Class 3 (Flammable liquids)

Class 4.2 and 4.3 (Spontaneously combustible chemicals)

Class of Chemical

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Class 5.1 (Oxidizing chemicals)

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Class 6.1 (Toxic chemicals)

Class 8 (Corrosive chemicals)

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Sulphuric Acid

H2SO4

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Health Hazards H2SO4

Acute - Swallowed

Can kill if swallowed.Will cause severe damage to the mucous membranes.May cause severe burns to the mouth,throat and stomach.Ingestion can cause nausea and vomiting.Ingestion can result in abdominal pain.

Acute - EyeCorrosive to eyes; contact can cause corneal burns.Permanent eye damage,including loss of sight,may occur.

Acute - Skin Highly corrosive to skin.Causes severe burns.

Acute - Inhaled

Harmful by inhalation.Possible harmful corrosive effects.High concentrations of vapour can cause severe irritation of the respiratory tract.

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First Aid

Swallowed

Rinse mouth thoroughly with water immediately.Give water to drink. DO NOT induce vomiting.Seek immediate medical assistance.

EyeImmediately irrigate with copious quantity of water for at least 15 minutes.Eyelids to be held open.Seek immediate medical assistance.

Skin

Wash affected areas with copious quantities of water immediately.Remove contaminated clothing and wash before re-use.Treat skin and clothing with 1% sodium bicarbonate solution to neutralizeacid residues.If irritation occurs seek medical advice.

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Inhaled

Remove victim from exposure - avoid becoming a casualty.Allow patient to assume most comfortable position and keep warm.Keep at rest until fully recovered.

If breathing laboured and patient cyanotic (blue), ensure airways are clearand have qualified person give oxygen through a face mask. If breathinghas stopped apply artificial respiration at once. In the event of cardiacarrest, apply external cardiac massage.Seek medical attention.

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Personal Protection

Protective Equip.

The following personal protective equipment must be worn.Overalls or similar protective apparel.Safety glasses,goggles or faceshield as appropriate.Rubber boots.Elbow-length PVC gloves.Splash apron.Wash contaminated clothing and protective equipment before storing/re-using.Avoid all contact.

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Sodium Hydroxide

NaOH

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Health hazards NaOH

Acute - Swallowed

Will cause severe irritation and chemical burns to the gastrointestinal tract. Swallowing can result in nausea, vomiting, diarrhoea, abdominal pain, swelling of the larynx and subsequent suffocation, perforation of the gastrointestinal tract, cardiovascular collapse and coma.

Acute - Eye

Corrosive to eyes; contact can cause corneal burns, possible permanent eye damage and blindness.

Acute - Skin

Will cause severe irritation and chemical burns in contact with the skin, which will result in itching, redness, swelling and tissue destruction.

Acute - Inhaled

Inhalation of mists will result in respiratory irritation and possibleharmful corrosive effects including lesions of the nasal septum, pulmonary oedema, pneumonitis and emphysema. Inhalation of mists at elevatedtemperatures will increase these symptoms.

Chronic

Chronic effects are unlikely due to the severity of acute effects.

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First AidSwallowed

DO NOT INDUCE VOMITING. Immediately wash out mouth with water and then give plenty of water to drink. SEEK IMMEDIATE MEDICAL ATTENTION.

EyeIf contact with the eye(s) occur, wash with copious amounts of water for approximately 20 minutes holding eyelid(s) open. Take care not to rinse contaminated water into the non-affected eye. SEEK IMMEDIATE MEDICAL ATTENTION.

SkinRemove all contaminated clothing. Wash gently and thoroughly with water for 15 minutes. Ensure contaminated clothing is washed before re-use or discard. If contact is more than of minor nature, SEEK MEDICAL ATTENTION.

InhaledRemove the source of contamination or move the victim to fresh air. Ensure airways are clear and have a qualified person give oxygen through a face mask if breathing is difficult. If victim has stopped breathing begin artificial respiration, or if heart has stopped, cardiopulmonary resuscitation. SEEK IMMEDIATE MEDICAL ATTENTION.

First Aid Facilities

Safety showers, eye wash and normal washroom facilities.

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General Safety Precaution1. Chemicals brought into the store are as per

MSDS submitted.2. Storage area has been cordoned off with

warning signs displayed.3. Chemicals are stored in a well-ventilated area

or open spaces.4. Ensure that suitable fire extinguishers are

provided at store.5. While handling the chemicals follow strictly

work practices, procedure.6. Workers handling the chemicals are equipped

with proper PPEs.7. All spillages are immediately cleaned up and

the place is rendered safe before commencing work.

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8. Impermeable clothing should be worn If large quantity of solvent is used.

9. Requisite quantity of chemicals alone should be stored and used.

10.Eye protection should be worn when chemical are being moved or transferred on site.

11.When mixing or pouring chemicals using temporary containers, container should be properly labelled.

12.Workers should be encouraged to wash before you eating and smoking at the workstation.

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13.If the skin is splashed with a chemical, it should be rinsed immediately with plenty of clean running water. Eyes should be flushed out thoroughly with water and should receive immediate medical attention.

14.If the worker is burnt by chemical, or feel unwell after using a Chemical, seek medical attention without delay.

15.If there is a spillage of chemicals on the ground or floor, this should be reported so that the right action can be taken, such as soaking it up with dry sand.

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chemical safety

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