Pesticides are sometimes made using processes familiar from chemistry or biology. Two examples of this can be seen in the decisions of the Ctgb board meeting of 28 April.
An ethylene-based agent may be used for ripening various fruits. A product based on the substance benzoic acid has been approved for a further period of 15 years as a plant protection product for combating bacteria, viruses and fungi. The Ctgb provides an explanation below.
Benzoic acid occurs naturally in large quantities and its use has its origin in a resin with an antimicrobial effect. It kills bacteria, fungi and viruses. Although the substance has been widely used in ancient times, that does not mean that it is by definition safe. That is why every product, no matter how logical the effect may seem, must be tested for safety for humans, animals and the environment.
The product with benzoic acid is approved for the disinfection of pots, containers, packing tables and tools on which the causative agents of plant diseases can remain. It is therefore not used directly on or in crops, which is why the Ctgb considers that there is no risk for the consumer of fruit and vegetables.
The risk assessment also shows that there are no unacceptable risks for people who apply the product or work with disinfected tools. The product is also safe for the environment: the permitted use concerns a very small amount of benzoic acid compared to the naturally occurring concentrations of benzoic acid. In addition, the substance breaks down quickly and organisms are hardly or not at all exposed due to the way of application in greenhouses and storage areas.
It’s a well-known tip: put a banana and avocado together in a paper bag and the avocado will ripen quickly. Bananas produce ethylene gas when they ripen, which means that other fruits – including other bananas – ripen faster. The tested product with ethylene gas already had an authorization for ripening bananas.
With the current board decision, the authorization is extended for the ripening of avocado, papaya, kiwi, mango, peach and citrus fruits. Ethylene is a common constituent of the air. Adding extra ethylene to unripe fruit in closed storage areas increases the concentration, as in the bag with banana and avocado.
Ethylene is gaseous and mixes with the air when the used storage is opened. The fruits that have been gassed therefore do not contain any gas and are safe for the consumer. The ethylene used is a fraction of what is present in the outside air and “disappears” therein, so that the agent used is also safe for the outside environment with the plants and animals present therein.