Stick to facts about glue toxicity.

A report in the London Telegraph draws attention to a scientific article that shows potentially toxic chemicals from label glues may be leaching through packaging and contaminating food. The article highlights an important point: consumers should be aware that dangerous chemicals can unintentionally end up in food. However, it does not examine the risk of chemical toxicity thoroughly, and, therefore, may overestimate the potential harm and environmental hazards the chemicals pose. 

Reports of yet another toxic chemical introduced unintentionally into the food supply can easily alarm the public. To avoid misleading readers, journalists should, where possible, probe how comprehensively the toxicity study was carried out and how relevant its results are likely to be for consumers.

In this case, the scientific study focused on measuring how easily different glues used in the food industry could move through various nylon-type packaging materials. This investigation of this permeability of glues was thorough and found that several components did indeed leach through the packaging materials. The researchers did not test these compounds for harmful toxic effects.

The reporter, however, drew attention to the toxicity of one of the glue components, stating that "one such adhesive [2,4,7,9-tetramethyldec-5-yne-4,7-diol] is in the "highly toxic" class along with other poisonous chemicals such as mercury, asbestos and hydrochloric acid." This statement is misleading. Experimental toxicity data available through government databases for this compound were not used to estimate this chemical's toxicity risk. The researchers based their estimate of risk only on a third-party classification system, often used to "guess" a chemical's toxicity based on its chemical structure. 

This scheme, however, can in no way replace toxicity data, especially in a case like this one, where the compound's toxicity data was readily available. The measured oral toxicity in the rat, in fact, categorizes the chemical in the U.S. Environmental Protection Agency's low toxicity category. This underscores the fact that the third party classification scheme used to "guess" the toxicity of this compound is just a crude estimation, and this should be made transparent in the report. It should be noted, however, that just because this compound was found to be of "low risk" for the rat, it does not mean it is necessarily "low risk" to humans as well.

The reporter should also include the quantities of the chemicals used in these glues, as well as the total quantity of glue produced. Neither the scientific paper nor the media report make it clear how much of the chemical identified as being most dangerous – 2,4,7,9-tetramethyldec-5-yne-4,7-diol – is used in these glues. 

Although it is unquestionable that chemicals in glues may pose a risk of food contamination, reporters should carefully present toxicity information and include other aspects of environmental risks – such as persistence and quantities produced  – in their reports of potentially dangerous environmental chemicals.