This guideline provides advice to applicants intending to register products for the control of pest species in animal housing, including sties, pens, stables, piggeries, poultry houses and feedlots. It covers situations in which residues may occur in livestock as a result of the use of a pesticide in or on the premises and structures of the housing facility; it does not cover direct application to livestock.
Specific animal housing residue trials are required when the label statements listed in the Residue restraints section are inappropriate or cannot be used. The studies are also required when the active constituent is a volatile compound that may migrate from its off-animal application site to contact animals or may contaminate their feed.
The degree of volatility of an active constituent is assessed from its vapour pressure, which is information required for the chemistry assessment of the compound.
An applicant may argue against the need for an animal housing residue study based on the vapour pressure of the active constituent, the general handling and animal husbandry practices in the relevant industry, and residue data derived from direct animal application studies.
For a compound in an uncertain category (that is, it has moderate or low volatility, but is known from metabolism studies to accumulate in edible animal tissues), an animal housing study will be required to be conducted under a maximum treatment regime.
The maximum treatment regime recognises that in many cases it is not practicable to remove animals from their housing while treatment takes place. An exception would be milking sheds. The study should be conducted using the species and animal housing situation that give the most potential for animal exposure.
It is essential that data are submitted to demonstrate residues resulting from a maximum treatment regime. This will enable maximum residue limits to be set high enough so that residue violations will not occur when the product is used according to the maximum label use pattern.
Data from overseas studies will be an acceptable substitute for local data if the work in those studies was carried out using the same use pattern and under similar husbandry conditions.
Residue studies should be conducted generally in accordance with this guideline. The Food and Agriculture Organization of the United Nations’ guidelines on producing pesticide residues data from supervised trials and in the relevant OECD Guidance Documents and Test Guidelines.
2. Directions for use
To minimise potential pesticide exposure of animals, labels must contain adequate directions for use in animal housing with guidance on application techniques (for example, for wall sprays and crack and crevice treatments).
Labels should contain a statement requiring thorough airing or ventilation of the premises after treatment, consistent with animal husbandry requirements.
All labels must include warnings (residue restraints) that, when followed, will minimise, if not eliminate, contact between animals and the pesticide. Basic warnings should be included in the residue restraints section of the label. You should propose other phrases if the phrases in the residue restraints section do not adequately cover a given situation (such as when animals cannot be removed, or are not normally removed, prior to treatment of their housing).
3. Housing selection
Animal housing typical of that in use in the relevant industry should be selected, again with the objective of generating maximum treatment regime residue data. Your report should include details of the layout of the site and the ventilation system in use.
4. Treatment method
In many animal husbandry situations it may not be practicable to remove the animals. Their presence during treatment further adds to the maximum treatment regime nature of the data.
In two separate premises, or in two isolated areas of the same premises, the treatment should be applied at the highest label rate, and at 1.5 to 2 times that rate, using the methods on the label. In a third separate area, animals should be kept as control animals. The animals in all three areas should be of the same breed and sex and of the same general age, weight and body condition.
If the label specifies multiple treatments, the trials should be carried out accordingly and the animals slaughtered or eggs/milk collected after all treatments are completed.
The housing should then be ventilated and cleaned as proposed on the label and the animals returned (if applicable).
At appropriate intervals as determined from other residue studies, or from metabolism data, groups of animals should be slaughtered or eggs/milk collected and analysed. Slaughter intervals should be determined so as to demonstrate that the residue has peaked and is declining.
If the chemical is known from previous data to have affinity for a particular indicator tissue, only that tissue, and meat, need to be analysed. Commodities to be sampled for various animal groupings are indicated in Table 1.
Table 1: Commodities to be sampled for various animal groupings
|Animal grouping||Preferred species||Commodities to be sampled|
|Lactating ruminant||Dairy cow||Meat, fat of meat, kidney, liver, milk|
|Monogastric animal||Pig||Meat, fat of meat, kidney, liver|
|Laying poultry||Domestic hen||Meat (with overlaying skin), fat of meat, kidney, liver, eggs|
5. Data reporting
Data should be reported according to the guideline, Reporting of residue trials.
6. Proposals for maximum residue limits
Applicants are required to propose maximum residue limits for the active constituent(s) contained in the product in all relevant food commodities.
7. Residue restraints
The wording used for residue constraints will vary depending on the use pattern and directions for use proposed for the label. Some examples are:
AVOID CONTACT WITH STOCKFOOD, FEED CONTAINERS, OR PLACES WHERE STOCKFOOD IS PREPARED OR STORED.
BEFORE USE—REMOVE ANIMALS. REMOVE OR COVER ALL EXPOSED STOCKFOOD, FOOD AND WATER CONTAINERS AND TROUGHS, PLACES WHERE STOCK FOOD IS PREPARED OR STORED, AND MILKING [OR SPECIFY] EQUIPMENT.
AFTER USE—WAIT [... HOURS/DAYS] AFTER TREATMENT, THEN THOROUGHLY VENTILATE TREATED AREA UNTIL DRY. CLEAN UP THOROUGHLY BEFORE ALLOWING RE-ENTRY OF ANIMALS.
SURFACES AND EQUIPMENT IN CONTACT WITH STOCKFOOD MUST BE THOROUGHLY CLEANED WITH AN EFFECTIVE CLEANING COMPOUND AND RINSED WITH WATER.