Download - 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