To provide context, this tutorial will follow a case study to further illustrate the steps you must take to maintain safety in the laboratory, and meet your regulatory obligations.
Jill and Chloroform
Jill has worked for a number of years in a University laboratory. 1 She recently became pregnant and newly-concerned about the chemicals she works with. One of the procedures she performs daily is of particular concern to her:
She uses a mixture of 750 mL chloroform with 10 mL of methanol, and 15 mL of H2O. She pours 10 mL of the mixture into several glass tanks located on her benchtop. Although the tanks have glass covers, vapors are emitted as she pours the liquid into the tanks. She rarely smells chloroform, but catches a whiff occasionally.
She would have used the laboratory’s fume hood, but it was full of equipment for an acid-misting procedure.
So, Jill lets her supervisor know her concerns. This tutorial follows the safety planning process that Jill and her supervisor use to determine Jill's and her future baby’s safety.
1. This case study and "Jill" are fictional.
2. All photos taken with this model were posed for the sole purpose of this tutorial. These photos do not reflect the safety practices of this model or her associated department.
Jill decides to reevaluate a procedure, in which she pours a mixture of mostly chloroform on a benchtop -- not in a fume hood. 2

Regulatory Obligations
The University must answer to federal and state health and safety regulatory agencies. This means while you are working in University laboratories, you must comply with any federal and state regulations that relate to your work.
If you do not follow safety practices in a University lab or research area you are breaking the law.
The following regulations control the manner that you may use chemicals: * Laboratory Safety Standard (regulated by Occupational Health and Safety Administration) * Employee Right-to-Know (ERTK) standards * your department’s Laboratory Safety Plan
By completing this tutorial you are meeting one of your regulatory obligations. The information in this tutorial is designed specifically to provide the knowledge you need to meet most regulatory obligations when working with chemicals. You will also need training from your PI or lab supervisor on hazards specific to your laboratory. Details about these regulations were provided in the first safety module: Introduction to Research Safety.
In our case study, it was actually Jill's required yearly update training, provided by her RSO, which led her to reevaluate the chloroform process. The RSO was reviewing the health hazards associated with chemicals in their department’s labs, and noted that chloroform is a potential human carcinogen that should be handled with caution. Since Jill had just learned she was pregnant she wondered whether her exposure was safe.

Principles of Safety
To maintain your safety and health in a laboratory, and to meet your regulatory obligations, it is important to follow a systematic planning process. This process is based on these three principles of safety: * Recognize the Risks * Evaluate the Hazards * Implement Controls

This tutorial provides the information you need to apply these three principles to your use of chemicals. However, you may also use these principles to manage biological and physical hazards. Jill and her supervisor will follow these three principles when they reevaluate the safety of the chloroform procedure.

Toxicity vs. Hazard
To accurately recognize, evaluate and control the risks associated with the chemicals in your laboratory, you will need to differentiate between the toxicity and hazard of any given substance.
Toxicity
Toxicity is the inherent ability of a material to cause adverse health affects. For example, mercury can cause memory loss, as well as gastrointestinal and neurological problems. Hence, mercury is a toxic substance.
Hazard
A hazard is the likelihood