Like most things in life, being safe while handling chemicals really boils down to common sense. A little planning and some basic precautions can keep accidents from becoming catastrophes. Safety precautions used should be designed around the most dangerous chemical to be handled. For example, if the experiment calls for the dilution of hydrochloric acid (HCL) in water, HCL is clearly the more dangerous of the two.
First, know the dangers of the chemicals to be used. A good place to find out information on the physical properties, safe handling, and reactivity of a chemical is its Material Safety Data Sheet (MSDS). These documents are shipped with all chemicals when purchased, or can be obtained directly from the manufacturer. Several chemical manufacturers have posted MSDS's online for easy access. An MSDS will also provide any special instructions for storage, clean up or fire control measures required.
Secondly, have a plan or outlined series of steps that will be done to perform the experiment. Planning out the experiment ahead of time will allow you to be prepared for physical hazards by wearing the appropriate Personal Protective Equipment (PPE). At minimum; safety glasses with side shields, lab coat or outer covering that can be removed in case of a spill and gloves should be worn while performing any experiment. In addition an apron, face shield, respirator or self contained breathing apparatus may be required. Again, the MSDS is a good place to look for information on what PPE is necessary for each chemical. Other physical hazards that should be noted are hot plates, flammable gases, or glassware that has the potential to break. Mechanical controls, such as fume hoods, should also be checked to ensure they are in good working order.
Finally, be prepared to dispose of the waste properly. Since most chemical experiments end up with compounds different from the starting ones, knowing their hazards is critical as well.
A few simple rules should also be followed when performing any chemistry experiment.
1.) Avoid contact with all chemicals, including fumes, whenever possible.
2.) Never taste a chemical.
3.) Only use laboratory grade glassware that is heat resistant, such as Pyrex or Kimax.
4.) Never heat a chemical that is completely sealed, always allow for venting.
5.) Always add acid/base to water, never the other way around.
6.) Change gloves frequently, even the best gloves can allow chemicals to soak through given enough time.
7.) Wash your hands frequently.
8.) Keep a supply of paper towels or Kimwipes available for small spills.
9.) Maintain the workspace so that it is clean and well organized.