Final answer:
The use of a graduated cylinder is not a safety concern when performing a substitution reaction using hydrochloric acid; it is rather a tool for accurate measurement within the lab.
Step-by-step explanation:
If a lab group were using hydrochloric acid to perform a substitution reaction, the concern that would not be relevant is the use of a graduated cylinder as a safety risk. Precautions commonly associated with hydrochloric acid include the potential for chemical burns, the need for proper eye protection, and the use of gloves to prevent skin contact due to the acid's corrosive nature. However, a graduated cylinder itself does not pose a direct chemical risk; it is a tool for measuring liquids with precision. When working with hydrochloric acid, appropriate laboratory techniques involve measuring the volume of acid or other solutions accurately, which is what a graduated cylinder is designed for.
Using a graduated cylinder safely assumes that students are trained in its proper use, such as reading the meniscus at eye level and handling the cylinder with care to avoid spills. It is the handling of hydrochloric acid and the reaction it is used in that require safety precautions, rather than the use of measurement tools like graduated cylinders.