Identification of Common Scented and Unscented Products

Did You Know…
Fragrances are all around us. Everywhere we go, fragrances impress us as being strong, weak, pleasant, unpleasant, fresh, woodsy, spicy, floral, and so on. We encounter fragrances in fine cosmetics, personal and household care products, plastics, automobiles, and the food we eat.

How do we detect all these different scents? The answer: with about 5 million olfactory odor detectors. If you think that’s a lot, think again. Dogs have 200 million detectors!

A label that says “fragrance free” doesn’t mean that the product has no odor. It usually means that no fragrances have been added. The chemical-based substances that make up most products frequently have a scent of their own. However, this scent can be unpleasant. Therefore, a fragrance is often added to make the product acceptable to the intended consumer. When a product is fragranced, the following attributes must be considered:

• The fragrance must maintain its relative strength over a long time period.
• The physical attributes of the product’s formulation must be preserved.
• The fragrance cannot affect the packaging components of the product.
• Besides appealing to consumers, the fragrance must cover up any offensive odor associated with the product.
  

Objective

• This warm-up exercise is intended to orient students to some of the common scents found in consumer items. Students will compare scented and unscented items.

Materials (Per Lab Station)

• Five zippered plastic freezer bags
• Filter paper (such as coffee filters)
• Unscented tissues
• Five different prepared samples:
  - Plain white soap
  - Menthol vapor rub
  - Ground nutmeg
  - Baby powder
  - New car smell (available as a spray from automotive stores)
• Two or more “fragrance-free” products, such as detergents, clothes softeners, deodorants, soaps, etc.
  Samples can be rubbed onto a piece of filter paper and placed into the bags. Label the bags with a letter. Other common odors can be used in place of the suggested ones.

Safety and Environmental Considerations
Although hazards with this exercise are minimal, read product labels. Students should wear protective eyewear.

Procedure

1. Carefully open one plastic bag and smell the odor that has been put onto the filter paper in the bag. Do not touch or remove the paper from the bag. Write on your data sheet what the odor reminds you of or smells like, and do not talk to the other people in your group.
2. Repeat this exercise with each of the other four bags. Breathe through an unscented tissue between samples. Be careful to open each bag one at a time so that the odors will not interfere with each other.
3. After each person in the group has decided on the odor of each sample, compare your answers and try to identify the sample.

Important Note: The information contained herein is presented in good faith. Teachers should verify their own results prior to the use of these lesson plans in a classroom setting. Use of this document is beyond the control of The Dow Chemical Company (“Dow”), The Dow Chemical Company Foundation (“the Foundation”), the National Science Teachers Association (“NSTA”), and/or the authors. Consequently, Dow, the Foundation, NSTA and/or the authors assume no obligation or liability for the use of these materials or the outcomes of any experiments and make no warranty, express or implied. Safety glasses or goggles should be worn at all times. Other protective clothing should be worn as instructed by the teacher. All materials should be properly disposed of as instructed by the teacher. The user of these materials is solely responsible for compliance with all federal, state and local law(s) concerning appropriate safety and disposal procedures.

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