• Subject: Carcinogens
• Subject area: natural sciences
• Age group: (minimum) 6th grade of primary school (11 years)

Purposes of the lesson

1. Students are trained in recognizing pictograms for hazardous substances, especially carcinogens, mutagens and CMRs.
2. Students outline suitable methods for safeguarding against and managing hazardous substances, particularly carcinogens, mutagens, and CMRs.
3. Students learn about the problems of chronic effects of CMR substances and appropriate preventive management.
4. Students identify the causes of food recalls through authentic situations and investigate the properties of the hazardous substance that led them to recall a particular food. Learn how to find food recall notifications.
5. Students learn about the safety data sheet as an “identity card” for hazardous substances and find out what information they can find about the substance in this document.
6. Students learn about ethylene oxide as an example of biocide and carcinogen.
7. Students learn that biocidal products are intended for the control of pests, moulds and bacteria, and that they contain hazardous chemical substances or microorganisms that may pose a risk to human, animal and environmental health.
8. Students learn about occupational cancer as an occupational chronic disease and the factors that can cause it, and know the measures to prevent exposure to dangerous substances that are potentially carcinogenic.

Activity 1: recall of various foods

• Students in groups receive and read examples of articles (journal texts) that deal with the recall of various foods due to the excessive content of carcinogens, e.g. ethylene oxide (News article 1: Recalled food is increasing- what is ethylene oxide and where is it found?).
• Students present to each other (in groups) the content/situation from individual articles (what the reason was for the recall).
• Students search for national and European websites where information on food recalls is published.

National food recall information is published on the website of the Administration for Food Safety, Veterinary Sector and Plant Protection (https://www.gov.si/drzavni-organi/organi-v-sestavi/uprava-za-varno-hrano-veterinarstvo-in-varstvo-rastlin/), European information can be found on the Safety Gate websites: EU rapid alert system for dangerous non-food products (https://ec.europa.eu/safety-gate-alerts/screen/webReport#recentAlerts) and Rapid Alert System for Food and Feed (RASFF) (https://food.ec.europa.eu/food-safety/rasff_en).

What to do if we have a recalled product at home?

“Consumers are advised not to consume the food, but to return it to the place of purchase. An invoice is usually required to reimburse the purchase price.”

Activity 2: understanding packaging labels

• Students look at various packaging containing dangerous substances. They find out in the group how we know or find out what substances are in a particular product and how we know if these substances are dangerous.
• They examine whether ethylene oxide or additive E410 are still present in products.

Activity 3: ethylene oxide

• The teacher prompts the students to think by asking questions: What kind of substance is ethylene oxide? How would you determine its properties? Shows a folder or binder with the safety data sheets of chemicals they have in the school laboratory.
• By individually reviewing various examples of safety data sheets, students discover their purpose and the type of substance data they contain.

What is Ethylene Oxide anyway?

Ethylene oxide is a carcinogenic substance that poses a risk to human health. “In the EU, the use of ethylene oxide in food production is not allowed, regardless of the method of production (organic/conventional). The maximum level of ethylene oxide residue is legally set at 0.05 mg/kg of food in the EU and represents the action limit with regard to food safety,” according to the NIJZ.

According to the Consumers Association of Slovenia, ethylene oxide is not a substance found on cotton swabs used in coronavirus tests. It has been used for a decade to sterilize such medical devices. However, its amount is so minor that its risk is virtually insignificant.

But it cannot be overlooked when ethylene oxide is found in food. It is also used as a pest control agent with a fumigation process. If this procedure is performed incorrectly, (too) large amounts of this substance can appear in food, which is now happening.

Activity 4: the characteristics of ethylene oxide

• The teacher distributes an ethylene oxide safety data sheet to all groups.
• Through examining the H- and P-phrases, students aim to identify the characteristics of ethylene oxide, which was responsible for the recall of the food that contained it.
• The teacher provides the students with an easy-to-understand explanation of the laws concerning the allowed amount of ethylene oxide in food, or its source (e.g. News article 2: “Ethylene oxide in food and risk to human health”).

Activity 5: Facts about Cancer as an Occupational Disease

• Students watch the animated film “Napo Raises Awareness about Hidden Killers”.
• In the group, they review the leaflets “Facts about occupational cancer” and conclude what cancer means, what a carcinogen is, how we label it and how we handle it.
• They learn about some situations or workplaces where workers are exposed to potentially carcinogenic substances and communicate what would be appropriate protections to minimize the risk of cancer.

Note: Variability in the order and combination of proposed activities is possible, especially in the case of the considered carcinogen.