Surface treatment or spray products against cockroaches (Tests indicated by ECHA BPR Guide: 2023 for PT18 products).
Non-choice laboratory test (based on CEB method Nº159: 2012).
Simulated use test or choice test (internal method).
The BPR Guide establishes the general tests and requirements that PT18 products must meet to demonstrate effectiveness against cockroaches, depending on the type of product and the intended use. Within surface treatment products or aerosols against cockroaches, a distinction is made between products for consumers, with lower requirements, and products for professionals, for which more complex tests and a higher level of effectiveness are required.
For products intended to be used as a general surface treatment or consumer spray, a non-choice laboratory test and a simulated or choice use test must be performed, while products intended for use as a general surface treatment or aerosol for professionals are required, in addition to a laboratory test and simulated use, a field test (not carried out at IVAMI).
In the non-choice laboratory test, cockroaches are exposed to surfaces treated with the test product, to evaluate the inherent contact toxicity or impairing effects of the active substance. Treated surfaces must include at least one porous and one non-porous substrate (or as claimed on the product label) representing surfaces that would typically be treated for cockroach control (e.g., ceramic tile, plywood, painted plywood, stainless steel, concrete…, etc.). In our laboratory, it is carried out following the CEB test method Nº159, by which surfaces of 15 x 15 cm of different materials are treated with the test product and, after drying, groups of cockroaches are placed on them and, after the contact time indicated for the product (which must be compatible with the time that cockroaches can reasonably be expected to be in contact with a treated surface under natural conditions, for example, 10 minutes - 1 hour), they are removed and evaluated. Mortality and annihilation or the effectiveness of affectation (state of intoxication and partial paralysis that usually precedes death). Furthermore, both the immediate effect (directly after drying of the surfaces) and the residual effect (after different times after application) can be evaluated, depending on what is desired to be declared for the test product. Mortality should be evaluated at the time the client wishes to declare, but at least after 24 hours. For residual effect testing, mortality is typically assessed between 1 day and up to 7 days post-exposure. The effectiveness of the effect is generally analyzed at intervals of 5 minutes to 30 minutes after exposure, and subsequently at 45 and 60 minutes. The time until 50% (KT50) and 95% (KT95) of the insects are affected is calculated statistically.
Note: The non-choice laboratory test is carried out using a procedure based on the CEB method No. 159, because, although the test procedure described in this document is followed, this method indicates certain discrepancies with the requirements of the BPR Guide in regarding the number of insects, replicas, minimum number of test surfaces, contact and evaluation time, so it is adapted to be carried out under the specific conditions of the BPR Guide.
Simulated use or choice tests are designed to mimic the practical use situation, where contact with the test product is optional for the cockroaches. In these tests, the cockroaches have the option of whether or not to be in contact with the product. That is, the cockroaches are introduced into a test chamber where half of the base surface has been treated with a test formulation and the other half is untreated. Food and water are placed in the untreated area that the animals can reach without crossing the treated area. In our laboratory, this test is carried out according to an internal method, following the instructions of the BPR Guide. As in the previous test, a variety of different treated surfaces can be tested depending on the intended use of the product (at least one porous and one non-porous surface) and evaluate both the direct and residual effects (at different times after treatment product application). As required by the client (or manufacturer), mortality is evaluated after the indicated times, but at least after 24 hours, and up to 7 days in residual efficacy tests.
Both the no-choice and simulated-use laboratory tests should be performed with two species of cockroach, a small species, usually the German cockroach (Blattella germanica), and a large species, either the oriental cockroach (Blatta orientalis) or the American cockroach (Periplanetta americana). Normally the German cockroach (Blattella germanica) and the oriental cockroach (Blatta orientalis) are used. Groups of cockroaches of the target species must be of a specific age and sex. It should be indicated whether the tests should be carried out with adults or nymphs; males, females or a mixed population (50:50). For products that claim “population control” (eradicates the cockroach population), different life stages of the cockroaches should be tested. Tests should be performed with 5 or more replicates, with at least 10 cockroaches per replicate. When only 3 replicates are used, at least 20 insects per replicate should be used. Additionally, all assays must include a negative untreated surface control, with insects from the same insect population and with the same number of replicates. The environmental conditions must be specified both during the conservation of the treated surfaces for residual efficacy tests and during the test itself (temperature, humidity, photoperiod). Generally, between 19-29ºC, although a higher temperature, for example 40°C, may be used when efficacy at high temperatures is claimed.
According to the BPR Guide, an insecticidal product intended for surface treatment or household sprays for cockroach control is considered effective if the following results can be achieved in the laboratory test and simulated use: ≥ 90% affectation within minutes of contact with the product (or according to the claim) and a mortality as indicated on the label, preferably ≥ 90% in 24 hours. Meanwhile, a surface treatment product or aerosol for professionals must demonstrate 100% mortality within a period of one hour for direct application and 100% mortality within 24 hours for the residual test after application of the product. in the non-choice and simulated use laboratory test (in both cases, a mortality between 90 and 100% can be accepted, as long as a nuanced explanation is given for the lack of complete control). For the field trial (not conducted at IVAMI) after a period of 2 to 10 weeks, population reduction exceeds ≥ 90% relative to untreated sites or pre-treatment levels. If retreatment is necessary, then 100% mortality should be achieved.
Variables to be chosen by the applicant
- Cockroach species for which efficacy is requested.
- Test type: laboratory test (non-choice), or simulated use test (choice test)
- Type of action (immediate effect or residual effect). If residual efficacy is requested, indicate the evaluation times after application of the product.
- Dosage rate on test surfaces (mL or grams/m2).
- The contact or exposure time of the cockroaches to the product (must be representative of real conditions).
- The time of evaluation of the effectiveness of involvement and mortality (generally the effectiveness of involvement normally in intervals from 5 minutes to 30 min, then again at 45 and 60 min, and mortality at least after 24 hours).
- The type of surfaces to be tested (at least one porous and one non-porous)
- Phases of the insects and sex of the requested cockroaches (adults/nymphs, males/females)
- Environmental conditions of temperature and humidity.