Public Release Summary - Tolylfluanid

Public Release Summary

Evaluation of the new active

TOLYLFLUANID

in the product

EUPAREN MULTI 500 WG FUNGICIDE

Contents

Foreword

List of Abbreviations and Acronyms

Summary

Introduction

Chemistry and Manufacture

Toxicological Assessment

Metabolism and Toxicokinetics Assessment

Residues Assessment

Assessment of Overseas Trade Aspects of Residues in Food

Occupational Health and Safety Assessment

Environmental Assessment

Efficacy and Safety Assessment

Labelling Requirements

Glossary

Toxicology

Following oral administration tolylfluanid is rapidly and extensively absorbed and quickly excreted, predominantly in the urine. Tolylfluanid has a low acute oral toxicity in rats but is moderately toxic to the guinea pig, rabbit and cat when formulated in an acetone/oil solvent. The acute dermal toxicity is low but the inhalational toxicity is moderate. The skin irritancy of tolylfluanid is slight, the eye irritancy is moderate to severe, and the compound is a skin sensitiser.

In chronic/carcinogenicity studies in dogs, rats and mice there was no evidence of carcinogenicity and although tolylfluanid was positive in two studies on its ability to damage genetic material in vitro, it was negative in 6 other studies and did not cause damage to genetic material when given to hamsters or mice. Four reproduction studies in rats at doses of up to 600 mg/kg bw/day demonstrated that at dose-levels of tolylfluanid that produced clear toxic effects in the parents, no adverse effects on reproduction were observed. Similarly, in two studies on the development of rat pups during pregnancy, the mothers were given doses of up to 1000 mg/kg bw/day of tolylfluanid during the period of foetal organ formation without any increase in malformations observed in the pups, although a reduction in placental and foetal weights was seen. A study in pregnant rabbits that were given up to 70 mg/kg bw/day revealed increased foetal death but no evidence of malformations.

Studies on the neurotoxicity of tolylfluanid in single and repeat dose studies found reversible behavioural and body temperature changes immediately following its acute administration in females, but that no long-lasting signs of neurotoxicity were produced.

Conclusion

Based on an assessment of the toxicology it was considered there should be no adverse effects on human health from the proposed use of tolylfluanid as a component of Euparen Multi 500 WG Fungicide.

Residues in Food and Trade Aspects

Data concerning residues in strawberries, metabolism in plants and animals, environmental fate and chemistry were considered as part of the residue evaluation of the application.

The metabolism studies showed that following oral administration to animals tolylfluanid was rapidly absorbed and excreted, mainly in the urine.

The plant metabolism studies support a residue definition of "tolylfluanid" as being appropriate. Such a definition is adequate for the purposes of monitoring Good Agricultural Practice.

Data from four Australian residue trials were presented. Tolylfluanid appears to be non-persistent and the number of applications does not significantly affect the residues observed at sampling. Overall the highest residue at the proposed withholding period (1 day) was 1.92 mg/kg. The Australian residue data submitted with the application support a MRL of 3 mg/kg and a withholding period of 1 day when Euparen Multi 500 WG Fungicide is used according to proposed Australian GAP.

No feed commodities in which tolylfluanid residues are expected are fed to animals in commercial situations. It is considered unlikely that detectable residues of tolylfluanid would occur in animals as a result of the use of Euparen Multi 500 WG Fungicide on strawberries and consequently no recommendations on animal feed commodity MRLs or animal commodity MRLs are being made at this time.

Due to the rapid breakdown and immobility in soil and rapid metabolism and excretion in animals, the use of tolylfluanid does not pose a significant risk of bioaccumulation in animals.

The theoretical maximum daily intake of tolylfluanid from the proposed use pattern is approximately 0.1% of the ADI of 0.1 mg/kg body wt/day.

Trade aspects

Although the quantities of strawberries exported are not insignificant they can be considered a minor export commodity in relation to Australia's overall export of horticultural commodities. The residue trials submitted with the application demonstrate that residues of tolylfluanid are unlikely to exceed the proposed Australian MRL when the product is used according to GAP. In addition, the proposed Australian MRL and residue definition are the same as those recommended by CODEX. Under the GATT agreement an MRL in place under CODEX should be adopted by importing countries even when there is a local MRL lower than the CODEX MRL. It is noted that some of the potential importers of Australian strawberries do not have national MRLs in place. It should be the Australian exporter's responsibility to determine whether the CODEX MRL is acceptable in such situations.

Occupational Health and Safety Aspects

NOHSC has conducted a risk assessment on Euparen Multi 500 WG Fungicide for use on strawberries. Euparen Multi 500 WG Fungicide can be safely used by workers when handled in accordance with the control measures indicated in this assessment.

Tolylfluanid is not currently listed in the NOHSC List of Designated Hazardous Substances. Bayer Australia Limited has classified tolylfluanid as a hazardous substance according to NOHSC Approved Criteria for Classifying Hazardous Substances. This classification is based on its acute inhalational toxicity, and irritant and sensitising effects. Euparen Multi 500 WG Fungicide was also classified by Bayer Australia Limited as a hazardous substance based on its skin sensitising effects.

Euparen Multi 500 WG Fungicide will be imported fully formulated. It is packaged in 400 g polybags. Transport, storage and retail workers will handle the packaged product, and could only become contaminated in the event of a packaging breach.

There were no studies available on the acute oral, dermal, and inhalational toxicity of Euparen Multi 500 WG Fungicide. The product is a moderate skin and slight eye irritant and causes skin sensitisation.

Euparen Multi 500 WG Fungicide is to be applied to strawberries at the rate of 200-1333 g/100 L water. The maximum application rate is 2 kg/ha. The water volumes will vary between 150 L/ha for low volume application and 2000 L/ha for high volume application. Spraying is to commence from flowering until the end of harvest at 7 to 10 day intervals. A one-day withholding period for harvesting strawberries is proposed.

No worker exposure data were available for tolylfluanid or Euparen Multi 500 WG Fungicide. The occupational health and safety risk assessment was based on estimates obtained from exposure models.

Instructions and Safety Directions are provided on the product label to minimise exposure to the product. Mixer/loaders and applicators need to wear cotton overalls buttoned to the neck and wrist and a washable hat and elbow length PVC gloves when opening the container, preparing spray and using the prepared spray. The following re-entry statement should appear on the product label and Material Safety Data Sheet: 'Do not allow entry into treated areas until the spray has dried. When prior entry is necessary, wear cotton overalls buttoned to the neck and wrist and a washable hat and chemical resistant gloves'. Additional information is available on the product Material Safety Data Sheet.

Environmental Aspects

The environmental hazard of tolylfluanid will be highest to organisms living in the vicinity where it will be applied. Residues would be expected on strawberry plant surfaces including the interrow plant cover and soil. Surface water, uncultivated land and nearby non-target plants (e.g. trees and grasses) may be contaminated through overspray, spray drift and/or run-off.

Tolylfluanid hydrolyses rapidly to dimethylaminosulfotoluidide (DMST) at alkaline pH with a half-life of <<10 min. The hydrolysis half-life increases progressively to 11.7 d as the pH decreases to 4. Photolysis is not likely to be a major route of transformation while metabolism in aerobic soil is initially rapid with DT50 values of <1-12 d. However, a significant lag phase is observed as small but detectable amounts (up to 7.7% of that originally applied) were found up to 99 DAT. The metabolite DMST also follows a rapid initial degradation with DT50 of 1.9-7.4 d followed by a lag phase.

Degradation of tolylfluanid in two natural sediment/water systems was rapid with undetectable concentrations by 14 DAT. However, DMST partitioned preferentially to the water phase with half-lives in the whole system of 42.1-76.4 d. Tolylfluanid is expected to be slightly mobile in soil but no parent or DMST were detected in leachate in several studies. After 40 d aging of parent compound in soil, 4.9% of the originally applied radioactivity (undetectable parent and 0.2% DMST) leached through 27 cm of soil while 75.1% remained bound in the top 9 cm of soil (68.5% was unextractable). Based on poorly described field dissipation studies, the half-life of tolylfluanid in one soil was 4.5 d with both parent and DMST nondetectable at 59 DAT. Other soils had DT50 values of 8.2-14 d with nondetectable concentrations by 59-60 DAT. In the best case aerobic soil DT50 of <1 d, Environment Australia modelled there would be no accumulation of tolylfluanid in soil. However, a worst case DT50 of 12 d would result in peak soil concentrations of about 2.5 mg a.i./kg soil after 10 weekly applications.

In water, the hydrolysis half-life would result in no accumulation from weekly sprays but the concentration of the metabolite DMST could continue to increase in the unlikely worst case direct overspray for 25 consecutive weeks and half-life of 76.4 d.

Tolylfluanid was practically nontoxic to Japanese quail in a 5-d dietary test which was supported by an unacceptable single dose acute oral study. The single oral dose LD50 to bobwhite quail was > 2,000 mg a.i./kg bodyweight which was practically nontoxic. The NOEC and LOEC to bobwhite quail in a one generation dietary toxicity study were 888 and 2,800 mg a.i./kg food, respectively, based on high mortality.

Technical and formulated (expected to behave similarly to the proposed formulation) tolylfluanid were very highly toxic to juvenile rainbow trout and golden orfe in acute 96-h exposures. The DMST metabolite was apparently slightly toxic but this result must be treated with extreme caution as it was a preliminary test. In chronic 21-d exposures, technical tolylfluanid was highly toxic to juvenile rainbow trout even though parent compound had hydrolysed completely to DMST by 21 DAT. When formulated, tolylfluanid was very highly toxic to trout after 21 d while DMST was only slightly toxic. Technical and formulated tolylfluanid were highly and very highly toxic to daphnids in standard 48-h experiments. However, only moderate to high toxicity was observed in two chronic 21-d exposures.

DMST was only slightly and very slightly toxic to daphnids in 48-h and 21-d exposures. Moderate to slight toxicity was observed when technical and formulated tolylfluanid were tested with algae for 72 h. DMST was slightly toxic in a 96-h test.

For earthworms, tolylfluanid alone and in a 4:1 mixture with tebuconazole were only very slightly toxic in 14-d exposures. Ten summaries on testing with honey bees were submitted, but were lacking study details and not used; a supplementary study was acceptable indicating relative nontoxicity after 48-h in oral and contact exposures. Formulated tolylfluanid at 2.58 kg a.i./ha was harmful to predatory mites but harmless to predatory heteropteran bugs at up to 2.42 kg a.i./ha.

Laboratory tests with a parasitic wasp showed a harmful effect at 200 g a.i./ha (5X lower than the proposed rate) but a 1.12 kg a.i./ha treatment on apple trees had no significant effect on the parasitisation efficiency of a different wasp. Formulated tolylfluanid was harmless to staphylinid, carabid and ladybird beetles at up to 2.64 kg a.i./ha while the green lacewing was unaffected by low application rates of 139-176 g a.i./ha.

Two loamy sands treated at 1.3 and 13.0 mg a.i./kg dw soil (with or without lucerne amendment) showed no lasting adverse effects on microbial carbon mineralisation by 28 DAT. When these soils were amended with ammonium sulphate and glucose, an adverse but tolerable reduction in nitrification was evident by 56 DAT. Ammonification processes were not measured.

There is no expected hazard to bobwhite quail from short term exposure to tolylfluanid residues in their food resulting from the proposed application. Even with the worst-case accumulation in soil from repeated spraying at 7 d intervals, the NOEC from chronic dietary studies is 2.8X higher than the EEC. Coupled with the birds' ability to leave the treated area and feed on noncontaminated items, the hazard to quail is expected to be acceptable. As toxicity studies on mallard ducks were not submitted, the hazard cannot be assessed.

Earthworms are expected to be adequately protected from both acute and chronic toxicity as are honey bees, predatory heteropteran bugs, the parasitic wasp Trichogramma dendrolimi and staphylinid, carabid and ladybird beetles. However, the hazard to the predator Phytoseiulus persimillios (used in IPM against the two spotted mite), wasps T. cacoeciae and Aphidius rhopalosiphi, green lacewings and predatory mites at the proposed application rate is unclear.

Growers intending to use Euparen Multi 500 WG Fungicide in IPM programs (e.g. release of predatory mites) should be made aware of the potential hazard to these organisms. Carbon mineralisation processes are not expected to be adversely affected even in the worst case soil accumulation, however, an adverse but tolerable reduction in nitrification may occur and the hazard to ammonification processes could not be assessed.

Water bodies adjacent to strawberry plots may be contaminated by tolylfluanid through direct overspray. Contamination outside the target area is likely to result from spray drift, particularly where sprayers producing small (vmd < 100 µm) droplets are used, and from run-off of material sorbed to soil and organic matter particles. In the worst-case scenario of a direct overspray of a 15 cm deep body of water with Euparen Multi 500 WG Fungicide, the expected environmental concentration of 0.67 mg a.i./L would result in Q-Values of 14 and 19 for fish and daphnids, indicating unacceptable risk for both. The Q-Value of 0.21 for algae indicates a risk that may be mitigated by restricted use but the hazard for macrophytes cannot be assessed due to lack of data.

The rapid hydrolysis of tolylfluanid should not result in accumulation of parent even with weekly applications, although the DMST metabolite may accumulate up to 4.5 mg/L in the best case and continually increase in the worst case. Chronic toxicity data only for rainbow trout were submitted which indicate no risk (EEC<NOEC) in the best case. As the worst case EEC continues to increase, the hazard appears unacceptable and requires clarification of the number of repeated applications and application interval to better define the EEC.

In the more likely exposure of water bodies by spray drift or run-off, a 10% drift would still result in unacceptable risk for fish and invertebrates, but acceptable for algae. A further refinement of drift (according to computer modelling) from a low boom ground sprayer with a buffer zone of 9.5 m would give a drift of 0.54% necessary to reduce the risk to fish and invertebrates to an acceptable level. Therefore Environment Australia suggested, and the company agreed to, a buffer zone of 10 m downwind of all strawberry fields to be treated with Euparen Multi 500 WG Fungicide. New information from the company suggests that applications are likely to be made approximately every 2 weeks in rotation with other fungicides. Therefore the worst case half-life of DMST of 3.8 mg/L is less than the NOEC for trout of 9.2 mg/L and the hazard is acceptable. As DMST partitions preferentially to water, contamination of water bodies by surface run-off may be expected but this hazard would be lower than above which is based on the worst case of repeated oversprays.

Efficacy and Crop Safety Aspects

Data presented by Bayer Australia Ltd supported claims that Euparen Multi 500 WG fungicide controls black spot and grey mould and suppresses powdery mildew on strawberries. The active ingredient is tolylfluanid a polyvalent fungicide with a protective mode of action. Tolylfluanid is closely related to dichlorfluanid, the active ingredient in registered fungicide Euparen. The activity of tolylfluanid is at least equivalent to, and in most cases better than dichlorfluanid.

Scientifically sound experiments were used to provide data. Adequate controls, replicates and treatments were used in all experiments.

Disease pressure for the four different experiments varied but was adequate to support efficacy work. Disease pressure is dependent on weather conditions which varied but sufficient disease development occurred to allow measurement of fungicide efficacy. Euparen Multi 500 WG fungicide provided at least equivalent control of black spot and grey mould in all experiments when compared with controls. For example, Euparen Multi 500 WG fungicide decreased the proportion of fruit affected by black spot and grey mould from 51% to <4% and 24% to 5% respectively. The fungicide also suppressed the development of powdery mildew. For example, Powdery mildew levels were decreased from 21% to <2%. Experiments for efficacy were conducted in Queensland and Victoria.

All data was statistically analysed using standard techniques and was correctly interpreted.

Crop safety

Three experiments were done, in Western Australia and Queensland, to determine the phytotoxicity of Euparen Multi 500 WG fungicide. Results from these experiments and the four efficacy experiments reported no observations of phytotoxicity. Even at extremely high rates of active ingredient only slight burning of leaves was observed under warm conditions.

Introduction

This publication provides a summary of the data reviewed and an outline of the regulatory considerations for the proposed registration of Euparen Multi 500 WG Fungicide, which contains the new active constituent tolylfluanid.

Responses to this public release summary will be considered prior to registration of the product. They will be taken into account by the APVMA in deciding whether the product should be registered and in determining appropriate conditions of registration and product labelling.

Written comments are invited and should be submitted by 4 July 2000, addressed to:

Colin Byrnes

AgVet Chemicals Evaluation Section

National Registration Authority

PO Box E240

KINGSTON ACT 2604

Phone 02 6722 4850 Fax 02 6272 3218

Applicant:

Bayer Australia Limited

Product details:

Euparen Multi 500 WG Fungicide is a water dispersible granule formulation containing 500g/kg tolylfluanid. Tolylfluanid is a polyvalent sulfamide fungicide with a protective mode of action. Tolylfluanid is closely related to dichlofluanid, the active ingredient in the registered product Euparen Fungicide Srpay. The activity of tolylfluanid is at least equivalent to, and in most cases better than dichlofluanid. The biochemical mode of action has not been fully elucidated although it is assumed that tolylfluanid, like dichlofluanid, interferes with several enzymes by reaction with -SH bonds.

The active constituent is manufactured by Bayer AG in Germany and the product will be formulated by that company, also in Germany.

The product is proposed to be registered for control of black spot and grey mould and suppression of powdery mildew on strawberries in all States.

Water dispersible granule or wettable powder concentrate formulations of tolylfluanid are registered in 24 countries under a variety of tradenames. The products are registered for use on strawberries in 17 of those countries.

Chemistry and Manufacture

The product proposed for registration in Australia is a water dispersible granule formulation under the trade name Euparen Multi 500 WG Fungicide.

The formulation storage stability and the physical and chemical properties of the formulated product and active constituent have been evaluated by the APVMA and are considered acceptable.

The source of Technical Grade Active Constituent to be used in the product has been approved by the APVMA (Approval No 51029).

Active constituent

The chemical active constituent in Euparen Multi is tolylfluanid which has the following properties:

Common name (ISO): tolylfluanid

Chemical name: N-(dichlorofluoromethylthio)-N',N'-dimethyl-N-p-tolylsulfamide (IUPAC)

CAS Registry Number: 731-27-1

Empirical formula: C₁₀H₁₃Cl₂FN₂O₂S₂

Molecular weight: 347.3

Physical form: Crystal solid

Colour: White

Odour: Aromatic

Melting point for E/Z mixture (1:1): 93°C

Octanol/water partition

coefficient (Kow): 3.90 at 20°C

Vapour pressure at 25^oC: 4x10^-4Pa (extrapolated)

Structural formula:

Formulated product

Product name: EUPAREN MULTI 500 WG FUNGICIDE

Active content: 500g/kg tolylfluanid

Formulation type: Water dispersible granule

Density: 0.65g/mL

Toxicological Assessment

EVALUATION OF TOXICITY

The toxicological database for tolylfluanid which consists primarily of toxicity tests conducted using animals, is quite extensive. In interpreting the data, it should be noted that toxicity tests generally use doses that are high compared with likely human exposures. The use of high doses increases the likelihood that potentially significant toxic effects will be identified. Findings of adverse effects in any one species do not necessarily indicate such effects might be generated in humans. From a conservative risk assessment perspective however, adverse findings in animal species are assumed to represent potential effects in humans, unless convincing evidence of species specificity is available. Where possible, considerations of the species specific mechanisms of adverse reactions weigh heavily in the extrapolation of animal data to likely human hazard. Equally, consideration of the risks to human health must take into account the likely human exposure levels compared with those, usually many times higher, which produce effects in animal studies. Toxicity tests should also indicate dose levels at which the specific toxic effects are unlikely to occur. Such dose levels as the No Observable Effect Level (NOEL) are used to develop acceptable limits for dietary or other intakes at which no adverse health effects in humans would be expected.

Acute Studies

Tolylfluanid has a low acute oral toxicity in rats (LD₅₀ > 5000 mg/kg) when formulated as a water based suspension but low to moderate toxicity (LD₅₀ > 1000 mg/kg) when formulated as a solution in an acetone/oil mixture. For the acetone/oil solvent, oral LD₅₀ values in other species were > 1000 mg/kg in mice and 250 to 500 mg/kg in guinea pigs. The acute dermal toxicity of tolylfluanid in rats was also low with an LD₅₀ > 5000 mg/kg for the aqueous suspension and > 400 mg/kg for an acetone/oil formulation, in both cases there were no deaths and no visible signs of toxicity. The inhalation LC₅₀ was 265 mg/m³ in rats following 4 h exposure, indicating a moderate toxicity rating for tolylfluanid by this route. Tolylfluanid produces a slowly reversible moderate to severe skin and eye irritation in rabbits and is a skin sensitiser in guinea pigs.

Euparen Multi 500 WG Fungicide is a moderate skin irritant and slight eye irritant in rabbits and a skin sensitiser in guinea pigs.

Short-Term Studies

Applications of tolylfluanid to the skin of rabbits at up to 500 mg/kg bw/day for 14 days in 2 studies caused no observable systemic effects. In one study slight surface skin effects were noted which included erythema and scaly skin changes, an increase in the skin thickness and signs of inflammation which appeared to reverse within 2 weeks of the discontinuation of tolylfluanid treatment.

In a study in rats treated with tolylfluanid at up to 225 mg/kg bw/day, given in their food, for 3 months the only effects of treatment related to lower body weight gains.

In rats fed food containing tolylfluanid at up to 9000 mg/kg of food, for 13 weeks (approximately equivalent to a dose of 450 mg/kg bw/day), the effects were limited to a slight disturbance of thyroid function and a slight disturbance in the level of liver enzymes in the blood. A slight reduction in weight gains and food efficiency were observed in groups treated at the highest level and water intake was increased in males at 9000 mg/kg of food, and in females at 1650 and 9000 mg/kg of food. In males at the highest treatment level a slight increase in liver weights was observed at the end of the 13-week treatment period. All treatment related effects either resolved completely over the 4 weeks following the treatment period or faded in intensity and approached the values observed for untreated animals.

In dogs fed for 13 weeks on food containing 0, 330, 1000 or 3000 mg/kg of tolylfluanid, treatment related effects were limited to those treated at 3000 mg/kg of food. These animals had an unkempt and emaciated appearance with lower activity levels, they ate less and gained less weight, had a progressive increase in alkaline phosphatase blood levels which appeared to reflect an absence of the normal age-related reduction in ALP values, and the liver weights were increased.

Long-Term Studies

Long term studies have been conducted in mice, rats and dogs at doses of up to approximately 750, 400 and 62.5 mg/kg bw/day respectively. No evidence of carcinogenicity was observed. In mice and rats the animals ate less and gained less weight at the highest doses used. In all three species evidence of liver and / or kidney damage was found which included; increased alkaline phosphatase levels (mice and dogs), increased liver and kidney weights (rats), increased liver enzyme levels in the blood of dogs (alanine amino transferase), and kidney function abnormalities (increases in blood urea and creatinine levels, urinary glucose levels - dogs). No structural changes were observed in the liver or kidneys of mice or rats but in dogs microscopic structural changes in the kidney were found which consisted of; dilatation, epithelial flattening and desquamation. In rats a hardening of the skull bones in male and female rats and a lengthening of the front teeth (incisors) in the males of the highest dose group were seen together with bone thickening on the internal surface of the skull and on the sternebrae. The NOEL from the dog study, 12.5 mg/kg bw/day, was the lowest of all studies evaluated and therefore sets the overall NOEL for tolylfluanid.

Reproduction and Developmental Studies

In two studies in rats to examine the effects of tolylfluanid on the development of the rat foetus the mothers were given oral doses of up to 1000 mg/kg bw/day during the period of foetal organ formation. No evidence of malformation was observed

Similarly in a rabbit study where the mothers were given tolylfluanid at oral doses of up to 70 mg/kg bw/day during the period of foetal organ formation there was again no evidence of malformation. Foetal loss increased at the highest dose however, but no effects were observed at doses of 25 mg/kg bw/day or less.

Genotoxicity

A total of 8 in vitro and 8 in vivo genotoxicity studies were carried out using tolylfluanid.

In 6 of the 8 in vitro studies (including studies on reverse mutations in S. typhimurium and Saccharomyces cerevisiae strains, enhancement of forward mutations in Chinese hamster ovary cells (HGPRT locus), and induction of DNA repair in primary cultures of rat hepatocytes) tolylfluanid showed no evidence of genotoxic activity. In the remaining 2 studies (mouse lymphoma TK +/- forward mutation assay and chromosome aberrations in human lymphocytes) positive findings for genotoxic activity were obtained. In both of these tests the positive results were found in both the absence and in the presence of metabolic activation but required the use of tolylfluanid concentrations which were toxic to the target cells.

To test whether the chromosome damage seen in vitro was likely to occur in a living animal four of the eight in vivo tests assessed, looked at this end point (chromosomal aberrations in Chinese hamster bone marrow cells or in Chinese hamster and rat spermatogonia) but found no evidence of genotoxicity. Tolylfluanid's ability to induce genotoxicity was also assessed in a mouse coat-spot test, a sister chromatid exchange study in mouse bone-marrow cells, a micronucleus test in mouse bone marrow cells and in a dominant lethal test in mice. Tolylfluanid gave no indications of genotoxic activity in any of the in vivo tests.

Neurotoxicity Studies

Other Studies

Acute toxicity studies with the major plant and animal metabolites of tolylfluanid demonstrated that these were similarly or less toxic than tolylfluanid itself. Studies on plant specific metabolites of tolylfluanid showed that none of these compounds produced genotoxic actions in Ames tests and the oral LD₅₀ values for all four compounds in rats was > 5000 mg/kg (the highest dose used).

The acute oral toxicities of triadimefon (LD₅₀ = 1045 mg/kg) and tolylfluanid (LD₅₀ > 5000 mg/kg) were determined in rats, and then the LD₅₀ values for mixtures of triadimefon (523 or 1045 mg/kg) plus tolylfluanid (2500 and 5000 mg/kg) were assessed. None of the combinations produced a greater than 50% death rate in the experimental groups. Thus, there was no synergism in the toxicity of the individual constituents of these mixtures.

Thiazolidin thiocarbonic acid (TTCA), an animal and plant metabolite of tolylfluanid, was tested for its ability to interact with thyroid enzymes. In these tests TTCA was found to have similar actions on the thyroid enzymes as that of some antithyroid drugs.

PUBLIC HEALTH STANDARDS

Poisons Scheduling

The National Drugs and Poisons Schedule Committee (NDPSC) considered the toxicity of the product and its active ingredient and assessed the necessary controls to be implemented under States' poisons regulations to prevent the occurrence of poisoning.

The NDPSC recommended that formulations containing tolylfluanid be placed in Schedule 6 of the Standard for the Uniform Scheduling of Drugs and Poisons (SUSDP). There are provisions for appropriate warning statements and first-aid directions on the product label.

NOEL/ADI

The most sensitive species tested was the dog with a NOEL of 12.5 mg/kg bw/day in a 1 year dietary study. In order to calculate an Acceptable Daily Intake (ADI) for humans, a safety factor is applied to the NOEL in the most sensitive species. The magnitude of the safety factor is selected to account for uncertainties in extrapolation from animal data to humans; variation within the human population; the quality of the experimental data; and the nature of the potential hazards. Using a safety factor of 100, an ADI of 0.1 mg/kg bw/day was established for tolylfluanid.

Metabolism and Toxicokinetics Assessment

Toxicokinetics and Metabolism

Tolylfluanid is rapidly and extensively absorbed following its oral administration and is then quickly excreted, predominantly in the urine but with a small proportion excreted in the bile and subsequently the faeces, resulting in > 90% of the dose excreted within 48 hours. Bioaccumulation of tolylfluanid or its metabolites was not observed. Low and moderate doses of tolylfluanid (2 or 20 mg/kg p.o.) and repeated low doses (2 mg/kg/day over 14 days) were handled in essentially the same manner. After a high dose (100 mg/kg p.o.) however, some evidence of limited absorption was observed. In the rat, tolylfluanid is rapidly metabolised, losing its fluorodichloromethylsulfenyl side-chain before under going further changes. Experiments in hens, goats and plants (apples, strawberries and grapes) suggested that similar routes of tolylfluanid metabolism were present in all three species.

Metabolism

Following oral administration to rats tolylfluanid was rapidly absorbed and excreted, mainly in the urine as 4-(dimethylaminosulfonylamino)benzoic acid. After 48 hours the amount of tolylfluanid equivalents in the body (excluding GIT) was less than 0.05% of the administered dose (2 mg/kg bw) or less than 0.2% of the administered dose (100 mg/kg bw). Elimination was nearly complete irrespective of dose level, sex or pretreatment.

A lactating goat study showed that tolylfluanid was readily eliminated in the urine with very little tissue retention. The goat in the study was administered [phenyl-UL-¹⁴C]tolylfluanid at 10 mg/kg bw on 3 consecutive days and sacrificed 2 hours after the last dose. Up to sacrifice the excretion totalled 59.7% of the totally administered dose with elimination in urine accounting for 49.4% of the total dose. At sacrifice the total residue in edible tissues and organs was 2.8% of the total dose. The major metabolite in all organs, tissues, milk and urine was found to be N-[4-(dimethylaminosulfonylamido)-benzoyl]-glycine which is the hippuric acid conjugate of N-4-(dimethylaminosulfonylamido)-benzoic acid (previously identified as a metabolite in rats).

In hens administered radiolabelled tolylfluanid orally in a single dose of 5 mg/kg bw or 3 consecutive daily doses of 5 mg/kg the excretion up until sacrifice amounted on average to 83.9% of the totally administered radioactivity. Only 0.01% of the total dose was determined in the eggs. At sacrifice the total residue in the edible tissues and organs was found to be 0.18% of the total dose. T he parent compound was not found in any of the biological materials tested. In muscle eggs and liver the major metabolite was 4-(dimethylaminosulfonylamido)-benzoic acid. In fat the major metabolite was dimethylaminosulfo-toluidid (DMST).

Metabolism studies in strawberries showed that the parent compound and DMST accounted for over 80% of the total residue. A significant portion of the tolylfluanid residue was found on the surface of the fruit. A further study in strawberries showed that the dichlorofluoromethylthio side chain of tolylfluanid is metabolised mainly to thiazolidine-2-thione-4-carboxylic acid (TTCA) and some carbon dioxide. Because the postulated intermediate thiophosgene is volatile it is difficult to draw conclusions about the likely presence of TTCA under field conditions.

Experiments with radiolabelled tolylfluanid in apples showed that unchanged parent compound accounted for up to 89% of the recovered radioactivity. DMST was identified as a minor metabolite along with two benzoic acid derivatives.

Metabolism of tolylfluanid in grapes was found to be more extensive than that previously identified in strawberries and apples. Unchanged parent compound and DMST were observed however the major metabolites were found to be glycoside conjugates of DMST.

Residues Assessment

Data concerning residues of tolylfluanid in strawberries, metabolism in plants and animals, environmental fate and chemistry were considered as part of the residue evaluation of the application.

Analytical methods

A validated analytical method was used to determine tolylfluanid residues in the Australian residue trials. The methodology involves solvent extraction of the fruit followed by clean-up on solid phase extraction cartridges and quantitation by gas chromatography. Recovery data was provided for determination of both tolylfluanid and DMST in apples, strawberries, raspberries, lettuce, tomatoes, grapes, grape juice and wine. The average tolylfluanid recovery in strawberry samples was of the order of 88-96% at fortification levels of 0.05-5.0 ppm. Under actual conditions of use the analytical Limit of Detection was set at 0.05 mg/kg. The methodology is considered adequate for determination of tolylfluanid and DMST residues in or on strawberries.

Storage stability

Storage stability studies of tolylfluanid and DMST residues in apples and strawberries were presented in the application. It was found that tolylfluanid and DMST residues were stable for up to 168 days in apples stored at -18°C and 811 days in strawberries stored at -20°C.

Residue definition

The plant metabolism studies support a residue definition of "tolylfluanid" as being appropriate. Such a definition is adequate for the purposes of monitoring Good Agricultural Practice.

Residue trials

Four Australian residue trials were presented. In most cases the trials were conducted at 1x and 2x the maximum application rate. The maximum application rate is expressed as either 1 kg ai/ha or 100 g ai/100L and trials were conducted at both of these rates. Plants were sprayed to the point of run-off in the trials conducted at the 100 g ai/100L application rate. The total number of applications varied between 4 and 7. The time between spray applications ranged from 6-15 days but was usually around 7 days. Samples of fruit were collected at 0-8 days after the final treatment and analysed to determine the tolylfluanid residue level. In all cases finite residues of tolylfluanid were observed in or on strawberries up to 8 days after the final treatment.

The results of the Australian residue trials conducted at the maximum application rate are summarised in the table below.

	Trial No.		Application rate		No. of applications	Tolylfluanid residue (mg/kg) Days after last application
						0		1	3	5	7
DJR 70/95		1 kg ai/ha		5		2.6	0.65		0.99	0.33	0.43 0.12 0.11 ¹ 0.36 0.42 ¹
RAV 010/97		1 kg ai/ha		5		1.53	0.73		0.7	0.39
RTL 509/98		1 kg ai/ha		4		0.65	0.96		0.57	0.2
RTL 407/96		100 g ai/100L		7		1.07	1.92		0.65	-
RTL 509/98		100 g ai/100L		4		1.3	1.53		1.38	0.93

1. Sample was collected 8 days after final treatment rather than 7.

Tolylfluanid appears to be non-persistent and the number of applications does not significantly affect the residues observed at sampling. Overall the highest residue at the proposed withholding period (1 day) was 1.92 mg/kg. The Australian residue data submitted with the application support a MRL of 3 mg/kg and a withholding period of 1 day when Euparen Multi 500 WG Fungicide is used according to proposed Australian GAP.

Processing studies

A British study investigating the fate of tolylfluanid and DMST residues after washing, jam making and preserve making was submitted with the application. Tolylfluanid residues in or on strawberry fruit were found to reduced by approximately 50% by washing the fruit in water. Both tolylfluanid and DMST residues were found to be depleted rather than concentrated during processing of strawberries.

Animal feed commodity MRLs and animal commodity MRLs

Estimated dietary intakes

The theoretical maximum daily intake of tolylfluanid from the proposed use pattern is approximately 0.1% of the ADI of 0.1 mg/kg body wt/day.

Bioaccumulation potential

The log octanol/water partition coefficient (log P_ow) of tolylfluanid was found to be 3.9. The FAO manual# designates compounds as fat soluble if they have log P_ow values greater than 4. Compounds with log P_ow less than 3 are not designated fat soluble. A log P_ow value of 3.9 indicates that tolylfluanid is on the borderline of the fat soluble designation. In the metabolism study of tolylfluanid in a lactating goat no parent compound was observed in any tissue. The major residue observed in the fat was DMST although only 2.8% of the total dose remained in the edible organs and tissues at sacrifice. Metabolite concentrations were highest in the kidney and liver rather than body fat. In general tolylfluanid was extensively metabolised and excreted. DMST is considerably more hydrophilic (log P_ow=1.6) than tolylfluanid so excretion is enhanced following hydrolysis.

Due to the rapid breakdown and immobility in soil and rapid metabolism and excretion in animals, the use of tolylfluanid does not pose a significant risk of bioaccumulation in animals. In the current application food producing animals are unlikely to be exposed to tolylfluanid as strawberries are not used commercially as a stock feed commodity.

Recommended amendments to the MRL Standard:

Table 1

Compound	Food	MRL (mg/kg)
ADD:
Tolylfluanid	FB 0275 Strawberry	3

Table 3

Compound	Residue
ADD:
Tolylfluanid	Tolylfluanid

The MRL recommendations indicated above will be conveyed to the Australia and New Zealand Food Authority (ANZFA) for consideration for incorporation into Standard A14 of the Food Standards Code and consequent adoption into the State/Territory food legislation.

Withholding periods:

The following withholding period statement is recommended in conjunction with the above MRL:

STRAWBERRIES: DO NOT HARVEST FOR 1 DAY AFTER APPLICATION

Assessment of Overseas Trade Aspects of Residues in Food

Overseas registration status

The overseas registration status (as at 30^th January 2000) of tolylfluanid formulations is summarised in the table below:

Country	Tradename	AI content (g/kg) / formulation type	Registered on Strawberries
Belgium	Euparen M	500 WP	Yes
Belgium	Euparen M WG	500 WG	Yes
Brazil	Euparen M 500 PM	500 WP	No
Croatia	Euparen Multi	500 WP	Yes
Czech. Republic	Euparen Multi	500 WP	Yes
Czech. Republic	Hattrick	500 WP	No
Demark	Euparen Multi	500 WG	No
Ecuador	Euparen M 50 PM	500 WP	No
El Salvador	Euparen Multi 50 WP	500 WP	Yes
Finland	Euparen M	500 WG	Yes
France	Methyleuparene	500 WP	No
Germany	Euparen M WG	500 WG	Yes
Great Britain	Elvaron M	500 WG	Yes
Guatemala	Euparen Multi 50 WP	500 WP	Yes
Ireland	Elvaron WG	500 WG	Yes
Kenya	Euparen M 50 WP	500 WP	No
Netherlands	Eupareen-M	500 WP	Yes
Netherlands	Euparen-Spuitkorrels	500 WG	Yes
Nicaragua	Euparen Multi 50 WP	500 WP	Yes
Norway	Euparen M	500 WG	Yes
Peru	Euparen M 50 PM	500 WP	No
Poland	Euparen Multi 50 WP	500 WP	Yes
Slovakei	Euparen Multi	500 WP	Yes
Slovakei	Hattrick	500 WP	No
South Korea	Baycor+Euparen-M 27 FW	27 FW	Yes
South Korea	Euparen-M 50 WP	500 WP	No
Spain	Euparen M 50 PM	500 WP	Yes
Sweden	Euparen M 50 WG	500 WG	Yes
Zambia	Euparen Multi 50 WG	500 WG	No

Overseas MRLs

The following overseas MRLs for tolylfluanid in strawberries have been established.

Country	Commodity name	MRL (mg/kg)
Spain	Strawberries	3
Netherlands ¹	Strawberry	10
Germany	Strawberries	5
Belgium	Strawberry	2
Austria	Strawberries	5
Finland ²	Berries	10
Denmark	Berries and small fruit	5
EEC (proposed)	Strawberries (field)	3
South Korea	Strawberry	3
Sweden	Fruits	3

1 Sum of tolylfluanid and DMST, expressed as DMST

2 Sum of dichlofluanid and tolylfluanid

CODEX Alimentarius Commission MRL

The current CODEX MRL for tolylfluanid in strawberries is 3 mg/kg. The residue definition is the parent compound ie. "tolylfluanid". The magnitude of the MRL and the residue definition are identical to the proposed Australian situation.

Export of strawberries from Australia

Total export of strawberries in 1996 was valued at $A11 million with major importers being Hong Kong ($A7.5 million), Singapore ($A1.3 million) and UK ($A0.7 million). The volumes of strawberries exported to various countries are summarised below.

Country of destination	Quantity (tonnes)
Hong Kong	3047
Singapore	661
UK	122
Netherlands	27
Indonesia	95
Belgium	20
UAEM	46
Germany	14
New Zealand	20
Switzerland	12
Italy	8
Saudi Arabia	23
Malaysia	29
New Caledonia	28
Other	42
Total	4194

Potential risk to Australian export trade

In assessing the potential risk to Australian export trade the volume of strawberry exports, the existence of a CODEX MRL and the Australian residue trials were all considered.

In addition, the proposed Australian MRL and residue definition are the same as those recommended by CODEX. Under the GATT agreement an MRL in place under CODEX should be adopted by importing countries even when there is a local MRL lower than the CODEX MRL. It is noted that some of the potential importers of Australian strawberries do not have national MRLs in place. It should be the Australian exporter's responsibility to determine whether the CODEX MRL is acceptable in such situations.

The risk to Australian trade posed by the use of Euparen Multi 500 WG Fungicide on strawberri

ac	active constituent
ADI	acceptable daily intake (for humans)
AHMAC	Australian Health Ministers Advisory Council
ai	active ingredient
BBA	Biologische Bundesanalstalt fűr Land- und Forstwirtschaft
bw	bodyweight
d	Day
DAT	Days after treatment
DT50	Time taken for 50% of the concentration to dissipate
E_bC₅₀	concentration at which the biomass of 50% of the test population is impacted
EC50	concentration at which 50% of the test population are immobilised
EEC	Estimated environmental concentration
E_rC₅₀	concentration at which the rate of growth of 50% of the test population is impacted
EUP	end use product
F	original parent generation
GAP	Good agricultural practice
h	Hour
HPLC	high pressure liquid chromatography or high performance liquid chromatography
id	Intradermal
ip	Intraperitoneal
IPM	Integrated pest management
im	Intramuscular
iv	Intravenous
in vitro	outside the living body and in an artificial environment
in vivo	inside the living body of a plant or animal
kg	Kilogram
K_OC	Organic carbon partitioning coefficient
L	Litre
LC50	concentration that kills 50% of the test population of organisms
LD50	dosage of chemical that kills 50% of the test population of organisms
LOEC	Lowest observable effect concentration
mg	Milligram
mL	Millilitre
MRL	maximum residue limit
MSDS	Material Safety Data Sheet
NDPSC	National Drugs and Poisons Schedule Committee
ng	Nanogram
NHMRC	National Health and Medical Research Council
NOEC/NOEL	no observable effect concentration/level
po	Oral
ppb	parts per billion
PPE	Personal Protective Equipment
ppm	parts per million
Q-value	Quotient-value
s	Second
sc	Subcutaneous
SC	suspension concentrate
SUSDP	Standard for the Uniform Scheduling of Drugs and Poisons
T-Value	a value used to determine the First Aid Instructions for chemical products that contain two or more poisons
TGAC	technical grade active constituent
vmd	Volume mean diameter
WG	water dispersible granule
WHP	withholding period