Presentation on theme: "There are simple DO and DO NOT rules in chemistry laboratory practices. It is expected that each student absolutely obeys these rules during the laboratory."— Presentation transcript:
There are simple DO and DO NOT rules in chemistry laboratory practices. It is expected that each student absolutely obeys these rules during the laboratory practice period. Protect yourself Therefore;
Wear appropriate dressing that covers your skin. Wear your laboratory coats. Wear eye protection (it will be given to you by the teaching assistant). Wear closed shoes. Tie your hairs from the back if you have long hairs. Follow the safety instructions. Keep your working area and laboratory environment clean and tidy.
Clean the spills immediately. Leave your bags and other personal things in the cabinets assigned for you outside the labs. Handle chemicals and chemical containers according to the guidelines. Wash your hands before leaving the lab. Clean the glass and metal materials you used before leaving the lab. Read the related laboratory experiment before coming to lab. If needed read additional course materials. Ask your Instructor any question if In doubt.
Eat, drink, or smoke inside the lab! Inhale, or taste chemicals! Leave your experiment unattended! Run any unattended and unauthorized experiment! Run in the lab! Leave experiment to the control of another friend Talk unnecessarily. If any doubt, talk to the teaching assistant! Leave the lab with your experiment gloves on your hands! Operate any instrument without attendance!
All chemicals must be evaluated as hazardous materials, not just to human beings but also to the environment. Therefore, it is the first safety principle in chemistry laboratory that all chemicals must be handled with care regardless of their identity and chemical properties. No chemical container should be left uncapped. There should not be any chemical container without a perfect label on it.
According to the basic chemical properties and their hazard, chemicals might be classified into different groups: Flammable Chemicals Corrosive Reagents Harmful and Toxic Reagents Oxidizing Agents Harmful and Toxic Agents
Flammable chemicals are those that easily burn or ignite causing fire. Most of the flammable compounds are organic solvents used in common such as alcohols (e.g., ethanol, and methanol), ethers (e.g., diethyl ether), esters (e.g., ethyl acetate), and ketones (e.g., acetone).
Never let a direct flame coming from a burner on flammable reagents or never leave flammable reagent containers unattended near by a burner. Unconscious and careless work with flammable reagents can cause an immediate fire. Therefore, it is quite important to use fume hood for transferring the desired amount of flammable reagent to another material.
Corrosive chemicals are those that cause damage when it contacts another material. They can give severe damages to human skin. Acids including but not limited to sulfuric acid, nitric acid, hydrochloric acid, hydrobromic acid are widely used corrosive reagents in chemistry practices. Concentrated alkali solutions including but not limited to sodium hydroxide, potassium hydroxide, triethylamine and ammonia are also corrosive. Some other examples of corrosive reagents are bromine solutions, thionyl chloride, aluminum chloride, dimethyl sulfate, and phenol.
It is quite important to accept all chemicals as toxic compounds and set, accordingly, the safety precautions. In order to prevent a severe contact with these reagents it is quite important to use fume hood. Similar to working with corrosive substances, if the toxic reagent is a liquid compound it is important to use glass pipettes with propipettes.
There are other hazard chemical groups such as oxidizers, Iachrymators, and irritants. Briefly, oxidizers easily cause fires when they get in contact with combustible materials. Lachrymators are some compounds that cause wetting of eyes strongly and immediately. Irritants are a group of corrosive substances. Some compounds also have a cross sign on it defining them as harmful and toxic.
Careless and unconscious practice can sometimes cause spills in laboratory studies. The first rule is the cleaning of the spills immediately. However, there are some rules to follow-up for the cleaning process.
Having the test gloves on, the responsible person for the spill must sweep the solid spills with paper towels and put in appropriate waste containers. If the spill is an acid or base solution it first must be neutralized and then swept with paper towels. If there is any doubt, the best behavior will be letting know the current laboratory instructor and other students working around. Spills generally happen when using the balances. It is the responsibility of a student to work carefully when weighing a substance employing the balance. If a spill happens the student has to clean the balance and its environment immediately.
Due to the hurry behavior of some students practicing in chemistry labs spills directly onto a person might happen. However, it is quite important to state that it is the responsibility of a student to protect himself through appropriate dressing, the lab coat, and the other protective equipment.
Waste for organic solvents: Organic solvents used are wasted into the waste for organic solvents. Waste for aqueous solutions: Waste that contains aqueous solutions must go into the waste of aqueous solutions. However, this should be done according to the instructions given by the teaching assistant. Waste for solid chemicals: Waste solid chemicals are collected in this type of waste. Test gloves are also collected in this type of waste.
Waste for silica: Silica is often used for chromatographic studies. Therefore, the silica waste must be separately wasted into the silica waste container. Wasting acid and base solutions: Acid and base solution must be neutralized first. Then, they are wasted through the general sink. General waste: General waste such as scratching paper and other material that are produced in the labs must be wasted to general waste present in the lab. Waste of broken glass material: Broken glass material must be disposed into this waste container.
It is important to be familiar with the principles that need to be performed if an accident occurs in the laboratory practices. Fire Chemical spills on body Cuts Allergic reactions and poisoning
Chemicals and all types of heaters are potential risk for fires in laboratory practices. When there is fire, the first thing expected from the students is to quit the lab without running and panic. If there is burning clothing, the first thing will be to lay down on the floor and shouting loudly 'help'. A panic and an immediate run will not stop the burning, in fact it will worse it..
It is also suggested to roll over near by the fire extinguisher or safety shower. However, it is so critical to keep in mind that water itself is not a fire extinguisher, in particular if the reason of fire is an organic solvent. Therefore, using a fire blanket and wrapping it onto the burning cloth will be the perfect move to stop burning of cloths. Never use a fire extinguisher on a person. Fire extinguishers and particularly sand is used to stop those types of fire. It is also important to keep in mind that medical assistance and fire office of the city must be immediately called in case of fire. Burns might happen not only related to fires but also when working with hot material and steam bath. In this case the first aid will be the treatment of burned tissue with cold water as much as possible and calling a medical assistance.
If there is a chemical spill on body, the immediate first aid will be washing that tissue with water as much as possible. For serious situations, there is emergency safety shower present inside the lab. All these applications are also valuable if there is spill on eyes. The safety shower also consists of eye-washing unit. Medical aid should be called in serious situations.
Depending on the degree of cut, the first aid application to cuts is changing. For small cuts, it is important to wash the cut tissue with water and then the bleeding must be stopped employing an appropriate bandage or plaster. However, if the degree of cut is serious a pad should be replaced directly over the wound and immediate medical assistance should be called. It is also valuable to raise the wounded tissue up and make the injured person lie down and wait quietly.
Any case of these situations medical aid must be called immediately.