TCE Contamination and Cleanup Curriculum
Take IT Off- Clean Those Hands!
Author: Chris Donovan
Editor: Stephanie Nardei
Time:
2 days
Preparation Collect 4 buckets of soil/sand mix that will be used as a
Time:
receptacle for collecting wastewater from hand
washing.
Mix up 4 different solutions of “degreaser” and have
enough for all classes.
Materials:
Eucerin© Cream or other mineral oil based cream
4 types of solvents: H2O, a mild bar soap, lemon juice,
detergent containing phosphates
4 large buckets with sand/gravel that students will use
to pour the waste water from washing their hands
Abstract
This is the initial Engage lesson for the earth science portion of the TCE learning cycle.
Part 1
Students, working for a large corporation have to decide on which hand-washing product is going
to be purchased for use by employees and customers in the restroom of their many offices and
outlet stores. It is meant to be seen as a routine activity, students washing their hands to get a
harmless “gunk” off. Only after they have washed their hands do they come to see that their
choice of the “best”, (in this case the most efficient type of solvent) to cut the grease off their
hands was not so harmless. The solvent in the water has to go somewhere and there is no
“away”. What ever is in the water may have some unintended consequences no matter what the
intentions of the user.
Students will grease up their hands with Eucerin© (or other mineral based cream) and rate the
most effective solvent. They will be given 4 possible choices and the cost of each. The
detergent solvent has the most effective degreasing properties and will be the cheapest to
purchase so it is thought that most if not all the student groups will decide to purchase this
product. They will have to set up a testing protocol and conduct their product test to justify their
decision.
Part 2--- 20 years later
Students will be testing the soil samples (waste water buckets from hand washing) so do
not throw the materials out.
This scenario mimics the TCE story and it is the unit’s goal to have the students grapple with the
ethical, scientific and technological questions surrounding the situation:


What is the role of science in our society and how do science and technology work
together to improved our lives?
What happens when the existing technology has not caught up to what science is
uncovering and making possible?
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TCE Contamination and Cleanup Curriculum
The goal of this unit is for students to ask what are we as a society presently doing which might
come back to bite us in the future. This enduring understanding of the dialogue between science
and technology is a main goal of this unit.
Objectives
Students will be able to:
 Design a protocol to test the effectiveness of four types of soaps.
 Conduct a scientific investigation
 Decide which soap product is the most effective based on the data they collected.
 Communicate and support their decision using evidence.
National Science Education Standard:

AZS1C1 PO 3
C2 PO 1, 2, 3, 4, 5
C3 PO 2, 4
C4 PO 3,4
Teacher Background
This scenario is aimed at getting the students to see how an everyday activity can have
unintended effects. It is also aimed at reducing the “blame factor” to zero. The debate over who
is to blame, if anyone, is both non productive and mute. Hughes Missile Systems does not exist
anymore and the use of TCE was an accepted practice in its day. The situation as we see it
today comes from advances in technology which were non existent in the war years plus the
priorities were different and can not be effectively judged by today’s standards and knowledge.
Keep the students blame quotient at a minimum and you will do yourself and them a favor.
This will set the scene for the culminating activity which asks the students what are we routinely
doing today which will prove to be harmful to us in future years?
Related and Resource Websites
Water Environmental Federation http://www.wef.org/Home
Activity
Scenario to be read to class:
You are the purchasing staff of a large corporation who has numerous manufacturing plants in
the area. Your workers are using a new product that is extremely greasy and they have been
complaining that the soap, which they have used for years, is just not effective in cleaning their
hands anymore. Employees are using 3 times as much soap now and still not getting their hands
clean and this is costing the company too much money.
Your mission is to run tests on 4 new products and determine which is most successful in cutting
the grease AND which is most cost effective. You finding will be written up and orally presented
to the class.
Students will be grouped in 4s.
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TCE Contamination and Cleanup Curriculum
A supply of Eucerin© moisturizing cream (the thick type) will be placed on each table with the
instructions that one student will take the sample and apply it to their hands. Give enough cream
so that it will not be easily rubbed in. The group will be presented with 4 degreasing products
that they have to test to see which is most effective in removing the Eucerin.
 The group has to design a test protocol
 Carry out the tests
 Make a determination based on data which degreasing product is the most effective in
removing grease.
 Present a written report detailing their finding attaching all methods and data.

DURING THE TESTING ALL WASTEWATER FROM HAND WASHING SHOULD BE
CAPTURED IN 4 BUCKETS OF SOIL/SAND MIXTURE.
Each bucket will be designated with the specific test material on it.
Closure
Students will report to class on the product that they found to be most effective and present their
data/evidence supporting their choice.
Embedded Assessment
Assessment will be based on the group’s written report AND on the individual Quick Write (QW)
to the promptA group representing one of the products you didn’t pick has brought the results of your tests into
question. Explain to them the scientific framework of your testing protocol and why you are
confident of it’s results…or are you??????? Is there something you might have missed?
Homework --- (and start of next class session)
This HW is meant to reinforce the fact that the problems stemming from the use of TCE were not
intentional.
Distribute to students the Household Hazardous Waste Chart (E1- HW)
Have student fill it out and return following day. The chart asks them about every day
products we use and find in our house and tests their knowledge on what is the proper
way of disposing of them. They will find out many of the “harmless” products we are
disposing of may come back to haunt us later. (Good way to tie in TCE use in the 40’s.)
Answers can be found on Water Environment Federation web site if students want to see
at home. Hand out key to all the next day to start a discussion.
Have student do a Quick Write (QW) to reflect on their learning from HW and on what
they do now which seems harmless but could be considered to be harmful in the future
when more is known about the environment and the effects we have on it.
http://www.wef.org/LearnAboutWater/ForThePublic/FactSheets/FactSheetDocuments/Ho
useholdHazardousWaste.htm (page will get you to chart)
http://www.wef.org/NR/rdonlyres/4B248DAF-88A1-4171-987FB36EDEEC17C9/0/hazardous_waste_chart.pdf (for chart)
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