Chemistry 101: Laboratory Rules

You are expected to adhere to the safety guidelines to ensure a safe laboratory environment for both yourself and the people you may be working near.

Additional safety precautions may be announced prior to experiments where a potential danger exists from explosive, highly toxic, or carcinogenic substances - which may be harmful to those outside of the lab and not directly present.

There is no such thing as 100% safe.

There always remains a certain unavoidable hazard associated with the use of a variety of chemicals and glassware, especially for explosive, highly toxic, and carcinogenic substances from the experiments which you will perform.

None.

Safety goggles must be worn at all times while in the laboratory. This must be followed whether you are actually working on an experiment or simply writing in your lab notebook.

Contact lenses are not allowed, even when worn under safety goggles, because fumes can accumulate under the lens and cause serious injuries or blindness.

Closed toe shoes and long pants must be worn in the lab at all times. Sandals and shorts are not ever acceptable.

Many labs additionally require a lab coat, which properly covers all sensitive skin of the arms, torso, and neck.

Long hair must be tied back when using open flames. In general it is recommended to be tied back at all times to avoid contamination.

Eating and drinking in any fashion are strictly prohibited in the laboratory.

Harmful contamination of water can occur readily (even if the bottle is only briefly open) if soluble toxic fumes are present.

Hands must be washed.

Always wash your hands before leaving lab. Contaminants can be deposited on door handles, railings, other non-lab persons, or yourself accidentally. This is clearly most important when planning on immediately eating or drinking after leaving the lab.

By means of your cupped hand, waft a small sample to your nose. Do not inhale these vapors - take in only enough to detect an odor if one exists.

Never taste anything. Never directly smell the source of any vapor or gas.

Ideally in a closed locker outside the lab room.

Some labs will have a separate space farthest from the experiment, designated for accessories. Coats, backpacks, etc., should not be left on the lab benches and stools. Lab chemicals can damage personal items.

These include fire extinguishers, fire blankets, full shower and eye-wash stations.

Many labs will also have gauze, burn cream, antiseptic, saline, alcohol, etc - but these are not generally considered emergency.

1. Flush immediately with cool water.

2. Inform the instructor and contact a health care specialist.

3. If not able to sufficiently treat on site, wrap with gauze to avoid additional contamination.

No unauthorized experiments should be performed during the original experiment window.

If a new experiment is deemed necessary, consult with your laboratory instructor to determine if there is time permitting or additional precautions required for that experiment.

Chemicals in the lab are marked with NFPA hazardous materials diamond labels.

Always know what chemicals you are using by reading the label twice before taking anything from a bottle.

4 = Deadly health hazard.

The blue left-most diamond is the health hazard rating and starts at 0 as the lowest (no hazard) to 4 as the highest (lethal hazard).

0 = Substance will not burn.

The red top-most diamond is the fire hazard rating and starts at 0 as the lowest (no hazard) to 4 as the highest (flammable at or below room temperature).

2 = Violent chemical change.

The yellow right-most diamond is the reactivity hazard rating and starts at 0 as the lowest (no hazard, stable) to 4 as the highest (extreme hazard, may detonate).

Trefoil = Radioactive.

The white bottom-most diamond is the specific hazard rating and contains any additional information for lab usage. Additional symbols like OXY (oxidizer) and ACID (an acid) are common as well.

-W- = Do not allow near water.

The white bottom-most diamond is the specific hazard rating and contains any additional information for lab usage. Additional symbols like OXY (oxidizer) and ACID (an acid) are common as well.

Chemical labels, or a chemical sheet, should accompany all stock bottles and be readily accessible at all times. They should indicate the following:

• signal words - DANGER, WARNING, CAUTION

• highly toxic materials marked as POISON

• precautionary measures useful in preventing physical harm to the individual

• instructions in case of exposure

• notes to physician for emergency treatment

• instructions in case of fire or chemical spill

• instructions for chemical handling and storage

Excess reagents are never to be returned to stock bottles. Dispose of the excess according to the safety protocol for that substance.

Unknown reagents are always disposed of via a specific waste container and should never be put down the drain.

Alcohols and acetone are highly flammable and found in most labs. Do not use them anywhere near open flames.

Always pour acids into water. Remember the mnemonic AA, for ‘Add Acid’.

If you pour water into acid, the heat of reaction will cause the water to explode into steam, sometimes violently, and the acid will splatter.

1. Flush immediately with copious amounts of water using the eye wash station in the lab.

2. Consult with your instructor.

3. Consult with a healthcare professional if necessary.

Never leave a burner unattended. Turn it off whenever you leave the workstation.

Additionally it is standard practice that the gas is shut off at the bench rack when you leave the lab. All labs have a back-up main gas shut-off for which the instructor is responsible.

• Yourself:

  • Beware of hot glass - it looks exactly like cold glass.

  • Clean up all broken glassware immediately and dispose of the broken glass properly.

• Others:

  • Never point a test tube or any vessel that you are heating at yourself or another person.

  • Walk through the lab in direct, deliberate movements, securely holding all glassware.

Notify supervisor/teacher immediately. Do not attempt clean-up of hazardous materials.

The teacher or stockroom supervisor is responsible for clean-up of mercury and other extremely hazardous spills.

Positioning and clamping the reaction apparatus carefully should allow manipulation without the need to move the apparatus until the entire reaction is completed.

A fume hood or fume cupboard is a type of local ventilation device that is designed to limit exposure to hazardous or noxious fumes, vapors or dusts. A fume hood is typically a large boxed region enclosing five sides of a work area, the bottom of which is most commonly located at a standing work height and the front of which is generally glass or Plexiglas.

Fume hoods are used whenever there is the danger of a toxic vapor being created.

1. All cylinders must be secured to a wall, bench, or other support structure using a chain or strap. Alternatively, a cylinder stand may be used.

2. Cylinders must be segregated by gas type (flammable, inert, etc.).

3. Gas cylinders must be stored away from heat sources and extreme weather conditions.

1. Eyes and skin. All affected areas should be rinsed continuously for 15 minutes.

2. Inhalation. Use a respirator and seek medical attention.

3. Ingestion. Call the poison control center. Do not induce vomiting unless directed to do so by a health care provider.

4. Injection. Wash the area with soap and water and seek medical attention, if necessary.

Factors that influence the susceptibility of an individual to the effects of certain substances include nutritional habits, physical condition, obesity, medical conditions, drinking and smoking, and pregnancy.

Due to individual variation and uncertainties in estimating human health hazards, it is difficult to determine a dose of a chemical that is totally risk-free.

Always assume containers are contaminated and wear appropriate gloves when handling acid/base containers.

Ex: Trifluoracetic acid (weak) can form hydrofluoric acid (strong) upon contact with moisture in the skin. Many acid/base burns are not painful immediately, and yet can require medical attention.

Group I metals react violently with water and are highly corrosive to eyes, skin, and mucous membranes.

Ex: Sodium will react immediately with saliva to cause serious burns and possible local combustion and even explosion of hydrogen in the mouth or esophagus.

• Substitution of a less toxic material

• Change in process to minimize contact with hazardous chemicals

• Isolation or enclosure of a process or operation

• Use of solutions to reduce generation of dusts or other particulates

• General dilution ventilation

• Local exhaust, including the use of fume hoods

Cease the experiment (unless doing so could cause more damage than not), and immediately contact a supervisor for replacement part(s).

1. Affirming that all aspects of your experiments have ceased and the apparatus has been dismantled and stored

2. Cleaning any exposed laboratory surface of possible contamination

3. Turning all gas lines, tanks, faucets to the off position - and checking even those that were not in use

4. Sealing all stock bottles fully and moving to proper storage

1. Affirming that all experiments have ceased

2. Turning all gas lines, tanks, faucets to the off position - including the main

3. Sealing all stock bottles fully and moving to proper storage

4. Affirming that the stock-room door, stock cabinets, fridge, or disposal areas are all closed and locked

5. Closing and locking the main access door to the lab

Deny access, and direct them to methods for contacting the lab supervisor or administration or janitorial/security staff.

Avoid providing access to even familiar individuals if you expect that they are acting in a suspicious fashion.