chemical hazard

Chemical Hazard

Definition of Terms

Toxic – substance that is harmful , which lead to temporary or permanent malady or death

Acute Toxicity – a quality of substance that produces a harmful effect within seconds, minutes or hours

Chronic Toxicity – a quantity of the substance thaw will take a long time to cause a harmful effect

Toxicity Evaluation

Reaction or Body changes

Complete chemistry

Dosage level

Secondary information

Route of Toxic Substances in the Body

1. Gastro-intestinal Tract

2. Skin

3. Lungs

Controlling Toxic Substances

Categories of Threshold Limit Value

T.L.V. (Time-Weighted Average) – gives exposure based on eight hours day, 40 weeks, which will not produce harmful effect

Threshold Limit Value Short Term Exposure Limit – this controls for substances higher level of exposure above T.L.V – T.W.A., for periods up to 15 min, provided no more than 4 short-term exposure are allowed in the day with the minimum spacing of one hour between the exposure periods

TLV-Ceiling – this is a level that mass never be exceeded for any time period

Poisonous Chemicals

Household – Insecticides, Inflammables and Extinguisher, Fire lighters, Fire starting tablets, Fire Extinguishers

Poisonous Chemicals

Cleansing Equipment – CCl4, Solvent distillate, Dye (NaOH), Ammonia, Bleach, Rug Cleaner, Wallpaper, Laundry Ink

Poisonous Chemicals

Medicine – Salicylates, Sedatives, Anti-epileptic Agent, Antihistamine, Cathartic Pills, Cough Mixture, Nose drop, Reducing or Sleeping Tablets, Cardiac Drugs

Poisonous Chemicals

Cosmetics

Hobby

Storage room – Paints and painting Supplies, Pesticides

Yard or Storage Garage

Safety Storage and Use

Medicine and Rodenticides must be stored in Lock Cabinets

Dust forming operations must be closed system with vent exhaust

Poisonous chemicals must be stored in lock cabinets

Dangerous solutions should not be stored in drinking/beverage glasses

Spraying down winds while painting

Combustion devices should be adequately vented

Education

All responsible person should be educated about the possible dangers of chemicals

Poison label must be placed

Proper education and Trainings on first-aid

Protective Clothing Equipment

Chemical Carcinogens

Cancer

1. Substance formed by normal processes of the body

2. Majority of human cancer are preventable

3. Concrete understanding of cancer

Controlling Carcinogenic Substances

1. Permitting use under hygienic control

2. Banning the use and changing to safer substitutes

List of Carcinogenic Substances

A. Substances prohibited in the United Kingdom

B. Substances controlled in the United Kingdom

C. Substances and processes carcinogenic to human health

D. Substances and processes suspected as carcinogenic to human

Animal Testing – exposure of animals to determine if the substance is a potential carcinogenic risk to humans

Epidemiological Surveys – Analysis of medical records to determine if there is a statistical increase of cancer in people exposed to a certain substance or process in comparison to people who are not exposed

Short-Term Screening Test – utilizes animal tissues as a test system

Harmful Effects of Chemicals to Human Health

Contact Dermatitis – cause by substance known as primary cutaneous irritants (e.g. Mineral Oils, Grease Solvents, friction, Strong alkali and acids, cement, radiation, and Physical agent- heat cold)

Accident by Gassing – inhalation of air containing toxic or corrosive gas.

Ex. Anoxia – lack of oxygen

1. Simple Anoxia – the amount of oxygen in air is reduced to a level that cannot adequately support respiration

2. Toxic Anoxia – occurs when oxygen is prevented from travelling through the body in the blood.

Hypoxia – oxygen deficiency that results from any interference with oxygenation of blood or inability of tissues to absorb oxygen.

1. Hypoxic Hypoxia – due to low oxygen tension in the blood

2. Hypemic Hypoxia – a disturbance impairing the ability of the blood carry oxygen to the tissue which involves loss of red blood cells and reduction of total hemoglobin.

Effect of Oxygen Deficiency in

Oxygen Content of Air (%) Effect

20.9 Normal, no effect

15 No immediate effect

10 Dizziness, Short breath

7 Stupor sets in

5 Minimum amount to support life

2-3 Death within 1 min

Effects of Carbon Dioxide

% Carbon Dioxide in Air Effect

0.04 Normal Air, no effect

2 Deeper Breathing , 30% increase

4 Much deeper breathing

4.5-5 Labored breathing

7-9 Limit of tolerance

10-11 Inability to coordinate

Corrosive Substances

Can cause chemical burns

Cause rapid destruction of the body at point of contact

Can be classified as:

A. Dehydration due to: Acids, Alkali and Acid Anhydrides

B. Reduction caused by reactive reagents: Na and K metals

C. Oxidation caused by reactive reagents: Nitric Acid, Chromium Trioxide and Bromine

Mechanism of Some Toxic Substances

Aromatic Amino and Nitro Compounds – oxidize iron(II) in the hemoglobin to iron(III) which reduces efficiency with which oxygen passes through the blood as the oxidized hemoglobin becomes inactive

Cyanide Ion – produce toxic action by deactivating enzymes that take part in the reaction which allows O to be used by the tissue

Hydrogen Fluoride – most corrosive agent

Hydrogen Sulphide – acts directly on the nervous system causing paralysis of the respiratory system

Mercury Vapor – if it is inhaled, it is absorbed by the lungs and oxidized into mercury ion

Phenol – capable of killing all biological cells

Material Safety Data Sheet

Section 1: General Data

- Company Name, Address, Phone

- Chemical Name and Family

- Trade Name

- Chemical Formula

- Chemical Abstract Number (CAS)

Material Safety Data Sheet

Section 2: Hazardous Ingredients

- Chemical Components

- Percent Concentration

- TLV (Threshold Limit Value)

- PEL (Permissable Exposure Limit)

Section 3: Physical Data

- Boiling Point - Water Solubility - Specific Gravity

- Vapor Pressure - %Volatility - Appearance

- Vapor Density - Evaporation Rate - Odor

Material Safety Data Sheet

Section 4: Fires and Explosion Data

- Flammable Limit

- Fire Fighting Procedures

- Fire and Explosion Hazard

- Flash Point

- Extinguishing Media

- Auto Ignition Temperature

Material Safety Data Sheet

Section 5: Health Hazard Data

- TLV/PEL

- effects of exposure

- Emergency First-aid

Section 6: Reactivity Data

- Stability

- Incompatibility

- Hazardous decomposition products

- Hazardous Polymerization

- Conditions to avoid

Material Safety Data Sheet

Section 7: Spill or Leak Procedures

- Clean-up Procedures

- Waste Disposal

Section 8: Special Protection

- Respiratory Protection

- Ventilation Requirement

- Gloves

- Eye Protection

Material Safety Data Sheet

Section 9: Special Procedures

- Handling and Storage

- Miscellaneous