In this activity, students will answer questions while watching the video, This Sandwich Will Save Your Life in an Arc Flash, from the Ingenious series produced by the American Chemical Society. Each episode investigates a different topic related to how leading-edge chemistry is taking on the world’s most urgent issues to advance everyone’s quality of life and secure our shared future. This episode investigates the composite fabrics that protect the lives of many people, like industrial workers, firefighters, and soldiers. When these workers encounter a fiery situation, they rely on protective clothing, designed using multiple layers of chemistry, to keep them safe.
By the end of this activity, students should be able to:
- Differentiate between natural and synthetic fibers.
- Explain how different types of fibers react differently to heat.
- Give a basic explanation of an Arc Flash.
- Describe the purpose of the layered design for protective clothing like an electrical worker’s coat.
This activity supports students’ understanding of:
- Lab Safety
- Physical Properties
- Chemical Properties
- Molecular Structure
Teacher Preparation: minimal
Lesson: 10-20 minutes
- Ingenious Video: This Sandwich Will Save Your Life in an Arc Flash
- Student Handout
- Computer and projector with volume, or student device to access video
- No specific safety precautions need to be observed for this activity.
- The Ingenious video series spotlights stories from the frontlines of chemistry research and development, where passionate innovators are stepping up to confront problems like pollution, overfishing, sustainability, and personal safety.
- In this video, This Sandwich will Save Your Life in an Arc Flash, students will learn about extreme cases of clothing catching on fire. While “stop, drop, and roll” may be a good idea sometimes, this video discusses situations where a better plan is needed. Every day, industrial workers, firefighters, and soldiers risk fiery situations that might seem hard to imagine. In an arc flash event, for one, temperatures can jump to metal-melting levels in milliseconds. How can anyone possibly survive that? Well, take a tip from a club sandwich, because it’s all about the layers. The composite fabrics that protect life and limb in these situations rely on some incredible, multilayered chemistry, including the ability to quickly form a protective carbonaceous crust around the wearer.
- The running time of this video is about 6 minutes and 30 seconds. As it is a short video and it moves quickly, you may want to show it twice, or instruct students to pause the video as needed on their own devices to ensure that they can record answers to all of the questions.
- The student questions are presented in sequential order in the video.
- An answer key has also been provided for teacher reference.
- The final questions are reflection-based and might be helpful in prompting a class discussion after students have a few minutes to answer them independently.
- The AACT classroom resource library offers many related teaching ideas. Below are several focused on the chemistry of fire and fire extinguishers:
For the Student
While watching the video, answer the following questions:
- True or False? Cotton is a cellulose-based fiber, meaning it is from a plant.
- What is an example of a synthetic fiber?
- What happens when a synthetic fiber is burned? How can this affect a person?
- True or False? An Arc Flash is not very intense. It is a long process of building heat.
- What temperature can be reached during an Arc flash?
- True or False? An Arc Flash can vaporize metals and release toxic gases.
- What is an important design consideration for an electrical worker’s coat?
- What element is graphite made of?
After you watch the video, reflect on the following questions:
- If one layer of a protective breaks down (doesn’t work properly), do you think the person will still be protected? Explain your thoughts.
- What additional questions would you have for a scientist in this field? What more do you want to know?