1 Physical Classification - 1 Physical classification - 2 Some - PDF document

Employee must be informed CHEMICAL SAFETY & CHOICE OF DISINFECTANT Ephy Khaemba - ILRI � Physical & chemical characteristics � The Right to Know Law Laboratory Management & Equipment Training Workshop 15 th to 19 th June 2015 � Chemicals in the Work Place Rabona, Rwanda � Location and Availability of MSDS and MSDB - Spill kits and Choice of disinfectants 1 2 Friday, June 19, 2015 Friday, June 19, 2015 Training will cover Why learn about chemical hazards � Recognize chemical hazards commonly encountered � Most common & significant health hazards in Labs � Chem. Can be hazardous for numerous � Provide examples of Physical and Health Hazards reasons & can combine with other chemical � How to Use and Understand a Material Safety Data Sheet / Material safety data base = new hazards � All hazards must be taken in to account when � Explain warning properties of various chemical hazards, how to control and evaluate them. using and storing chemicals � Chemical Hygiene Plan � Spill kits and how to select disinfectants 3 4 Friday, June 19, 2015 Friday, June 19, 2015 Chemical Hazard recognition Physical Classification Chemicals may be found in different forms and the danger is � Degree of hazard associated with a specific determined by its form: chemical will depend on: � Solid: Lead pipe ( sanded & welded = lead dust / fumes; Nickel contact = dermatitis); pesticides evaporate direct from solid; � Its physical & chemical properties contact with acids & bases. � Liquid: contact with skin- absorption, inhaled, � Its toxicity - The degree of hazard depends on its ccts and handling - eg. Inhalation is the 1 0 entry route of chemicals into the � The way it is used in the Lab body � The environment in which it is encountered - Due to this, vapor pressure in vital to determine the hazard ( low vp= low airborne concentration= low toxicity & viz avi. 5 6 Friday, June 19, 2015 Friday, June 19, 2015 1

Physical Classification - 1 Physical classification - 2 � Some chemicals help other contaminants to � Gases and vapors: At gas state molecules are penetrate the skin. e.g. Dimethyl sulfoxide is unrestricted by cohesive forces. extremely well absorbed in the skin and is used in - Vapors are evaporation products of medicine to transport drugs in the body. chemicals that are normally liquids at room � Liquids present a splash hazard; ( goggles, T 0 faceshields, gloves coveralls) to prevent aye and / or - Routes of entry to the two: inhalation, skin contact injection, ingestion and eye/ skin contact. � Some liquids combine with others = new hazards: house hold bleach and ammonia 7 8 Friday, June 19, 2015 Friday, June 19, 2015 Physical classification - 3 TRIVIA � Aerosols: Invisible/ visible fine solid or liquid � The degree of chemical hazards depends on particulate matter in the air (dust, fumes , certain properties. Which of the following mist, fog, smoke, smog). - Knowledge on how various aerosol are physical properties are potential skin produced assists you anticipate where hazards? aerosol hazards may exist in the Lab. - Are hazardous when in contact with: eye, skin, � 1). Solid respiratory system and ingestion system. � 2). Liquid **Know all routes of chemical exposure as per specific hazard** � 3). Aerosol � 4). Gas and vapor 9 10 Friday, June 19, 2015 Friday, June 19, 2015 Chemical Characteristics Characteristics 2 � Understanding chemical ccts you anticipate � Information found on MSDS: to use in Lab. helps you identify the hazards � Solubility of a chemical & protect yourself. � Explosive limits of a chemical � This is obtained from MSDS / MSDB of a � Melting point of a chemical specific chemical. � Specific gravity and density � MSDS must be available in the work place � Vapor density and easily accessible to every employee. � Flash and boiling points � All must understand how to use it. � Vapor pressure and auto ignition temperature 11 12 Friday, June 19, 2015 Friday, June 19, 2015 2

Characteristics 3 Characteristics 4 � Chemical Flashpoint: The lowest T o at � Vapor pressure: - Is the pressure exerted which a liquid gives off enough vapor to form on the sides of the container, an ignitable and produce a flame in the and is promotional to T 0 (mm Hg). presence of heat source. - The higher the vapor pressure - Ignition continues infinitely so long as the T 0 the more volatile the liquid. is above the flash point! Explosive limits: Range of concentration of gases in air to support explosive process. Its - Some liquids have low while other have high measured by UEL/LEL flash points. 13 14 Friday, June 19, 2015 Friday, June 19, 2015 Trivia WARNING PROPERTIES � Vapor pressure is pressure exerted by a � Will alert you on the presence of chemical in vapor against the sides of a closed container. the air:- If vapor pressure is temperature dependent, � Odor threshold (airborne concentration) what does a container of a liquid with the � This must be taken by caution due to ranges sides pushed out mean? in individuals sense of smell. � 1). The container is old 2). Container is � Sense of smell can be reduced by: allergies, leaking. 3). Was exposed to heat 4). Was head colds and olfactory fatigue. exposed to cold. 15 16 Friday, June 19, 2015 Friday, June 19, 2015 WARNING PROPERTIES-1 TRIVIA � Odor threshold is the concentration at which � Color product: (nitric acid = red, chlorine hazardous chemicals can be detected by =blue) smell. Which of the following choices has the � Other sensory signal: mild irritation of eyes, ability to impair the bodies ability to smell? nose or throat. � 1). Allergies � Some chemicals will produce a taste before � 2). A head cold or instead of odor or irritation. � 3). fatigue � 4).All the above 17 18 Friday, June 19, 2015 Friday, June 19, 2015 3

Chemical hazard evaluation Chemical grouping MAJOR GROUPS (categories) � Identify materials available & obtain knowledge on their hazardous status Be aware that some chemicals have multiple hazards and therefore require further segregation � Ensure employees are aware of them and � Flammables are accessible to the hazards information � Oxidizers ( Reactives health;Toxic, irritants) � Take precaution if you are unsure that a pH Value: Acid, Neutral, Base (Corrosives) � � Inorganic or Organic ( CH 2 0H, Ca, Cd, H 2 SO 4) hazard exists Solid or Liquid; Store separately to avoid accidents in case of � Check for the presence of corrosives chemical/liquid spill 19 20 Friday, June 19, 2015 Friday, June 19, 2015 Grouping - 2 TRIVIA � Chemical Name Hazard pH � Which of the following corrosives forms the greatest number of hydrogen ions? � Sulfuric Acid Corrosive � Acids � Isopropanol Flammable � Bases � Acetic Acid Corrosive � Halogens � Nitric Acid Corrosive � Ethyl Alcohol Flammable � Formalin Toxic 21 22 Friday, June 19, 2015 Friday, June 19, 2015 Chemical Hygiene Plan Chemical disposal � To out line procedures to protect employees from � Consider the hazard associated with use of health hazards associated with chemicals the chemical. � Follow OSHA / WRAIR / CDC guidelines � STATE the general safety precautions � Controlled by SHEMP manager necessary for the handling, storage, and � Include occupational health surveillance � Copies of job hazard analysis disposal of corrosives. � Annual CHP inspection � Chem. Inventory � Proper & adequate PPE 23 24 Friday, June 19, 2015 Friday, June 19, 2015 4