An image of toothpaste on a brush ( AFP / SAUL LOEB)

Posts falsely claim 'colour stripes on toothpaste tubes reveal ingredients'

Copyright AFP 2017-2022. All rights reserved.

An image of several toothpaste tubes has been shared repeatedly on social media, with posts claiming the colour of the stripes at the bottom of the tubes gives information on the paste's ingredients. This is false. The stripes, technically known as an "eye mark", are in fact used to aid in the manufacture of toothpaste tubes so that the tube may be correctly cut and sealed, according to industry experts.

The photo was shared among Sri Lanka-based WhatsApp users on October 4, 2022.

It shows three toothpaste tubes with coloured stripes at the bottom of each tube highlighted with circles.

The Sinhala-language text superimposed on the photo translates to English as: "Are you aware of this as a toothpaste user? Colour of the stripe at the bottom of the tube means:

"Green - 100% natural / blue - natural + ayurvedic / red - natural + artificial chemicals / black - 100% artificial chemicals

"Please pay attention to this because a lot of users continue to buy toothpaste with the black bar."

Screenshot of a misleading Whatsapp message, taken on October 10, 2022

An identical claim has been shared among Sri Lankan Facebook users since at least 2017 as seen here, here and here.

It has been shared in other languages, including Chinese and Indonesian, since at least 2013.

However, the claim is false.

Manufacturing aid

A keyword search on Google found this article published by Colgate, an American brand that produces oral hygiene products, including toothpaste.

The article, titled "What is a Toothpaste Color Code?", reads in part: "We're sure you're wondering... why are there color blocks on toothpaste tubes then?

"They actually help in the manufacturing of the toothpaste tubes by telling light sensors where the end of the tube is so that it can be cut and sealed properly."

The stripes, technically known as an "eye mark", are a small rectangular printed area located near the edge of printed flexible packaging material, which can be found on product packaging for all sorts of things, not just toothpaste.

Jonathan Kusu, a packaging engineer at global cosmetic firm Avon, told AFP in 2019: "These rectangles (eye marks) are placed in order to centre the decoration of the tube, which is cylindrical, with a front and a back.

"The rectangle is to be read by the machine which, from that mark, will leave the cylinder centred and divided between front and back and then seal it."

Kusu explained the colour of the eye mark is decided based on the colour of the product's packaging.

"If the tube is light-coloured, a black rectangle is used because the machine has to have a difference in contrast to be able to read it. Conversely, if the tube is dark, a white one is used," he said.

Below is a photo taken by AFP of a toothpaste product available in Sri Lanka that has a green eye mark on its tube.

Photo taken by AFP of a toothpaste product available in Sri Lanka that has a green eye mark on its tube. We have circled the ingredients and eye mark in red

Contrary to claims made in misleading social media posts, the product contains various synthetic substances, including sodium lauryl sulphate and sodium benzoate.

October 20, 2022 This article has been updated to include archived links of the misleading posts and to correct the description of Colgate.