Towards a mechanism-based approach for the prediction of nongenotoxic carcinogenic potential of agrochemicals.

Chemical substances are subjected to assessment of genotoxic and carcinogenic effects before being marketed to protect man and the environment from health risks. For agrochemicals, the long-term rodent carcinogenicity study is currently required from a regulatory perspective. Although it is the current mainstay for the detection of nongenotoxic carcinogens, carcinogenicity studies are shown to have prominent weaknesses and are subject to ethical and scientific debate. A transition toward a mechanism-based weight-of-evidence approach is considered a requirement to enhance the prediction of carcinogenic potential for environmental (agro)chemicals. The resulting approach should make optimal use of innovative (computational) tools and be less animal demanding. To identify the various mode of actions (MOAs) underlying the nongenotoxic carcinogenic potential of agrochemicals, we conducted an extensive analysis of 411 unique agrochemicals that have been evaluated for carcinogenicity by the United States Environmental Protection Agency (US EPA) and the European Chemicals Agency (ECHA). About one-third of these substances could be categorized as nongenotoxic carcinogens with an average of approximately two tumor types per substance, observed in a variety of organs. For two-third of the tumor cases, an underlying MOA (network) could be identified. This analysis demonstrates that a limited set of MOA (networks) is underlying nongenotoxic carcinogenicity of agrochemicals, illustrating that the transition toward a MOA-driven approach appears manageable. Ultimately the approach should cover relevant MOAs and its associated key events; this will also facilitate the evaluation of the human relevance. This manuscript describes the results of the analysis while identifying knowledge gaps and necessities to achieve a mechanism-based weight-of-evidence approach.

A comprehensive view on mechanistic approaches for cancer risk assessment of non-genotoxic agrochemicals.

Currently the only methods for non-genotoxic carcinogenic hazard assessment accepted by most regulatory authorities are lifetime carcinogenicity studies. However, these involve the use of large numbers of animals and the relevance of their predictive power and results has been scientifically challenged. With increased availability of innovative test methods and enhanced understanding of carcinogenic processes, it is believed that tumour formation can now be better predicted using mechanistic information. A workshop organised by the European Partnership on Alternative Approaches to Animal Testing brought together experts to discuss an alternative, mechanism-based approach for cancer risk assessment of agrochemicals. Data from a toolbox of test methods for detecting modes of action (MOAs) underlying non-genotoxic carcinogenicity are combined with information from subchronic toxicity studies in a weight-of-evidence approach to identify carcinogenic potential of a test substance. The workshop included interactive sessions to discuss the approach using case studies. These showed that fine-tuning is needed, to build confidence in the proposed approach, to ensure scientific correctness, and to address different regulatory needs. This novel approach was considered realistic, and its regulatory acceptance and implementation can be facilitated in the coming years through continued dialogue between all stakeholders and building confidence in alternative approaches.

Is current risk assessment of non-genotoxic carcinogens protective?

Non-genotoxic carcinogens (NGTXCs) do not cause direct DNA damage but induce cancer via other mechanisms. In risk assessment of chemicals and pharmaceuticals, carcinogenic risks are determined using carcinogenicity studies in rodents. With the aim to reduce animal testing, REACH legislation states that carcinogenicity studies are only allowed when specific concerns are present; risk assessment of compounds that are potentially carcinogenic by a non-genotoxic mode of action is usually based on subchronic toxicity studies. Health-based guidance values (HBGVs) of NGTXCs may therefore be based on data from carcinogenicity or subchronic toxicity studies depending on the legal framework that applies. HBGVs are usually derived from No-Observed-Adverse-Effect-Levels (NOAELs). Here, we investigate whether current risk assessment of NGTXCs based on NOAELs is protective against cancer. To answer this question, we estimated Benchmark doses (BMDs) for carcinogenicity data of 44 known NGTXCs. These BMDs were compared to the NOAELs derived from the same carcinogenicity studies, as well as to the NOAELs derived from the associated subchronic studies. The results lead to two main conclusions. First, a NOAEL derived from a subchronic study is similar to a NOAEL based on cancer effects from a carcinogenicity study, supporting the current practice in REACH. Second, both the subchronic and cancer NOAELs are, on average, associated with a cancer risk of around 1% in rodents. This implies that for those chemicals that are potentially carcinogenic in humans, current risk assessment of NGTXCs may not be completely protective against cancer. Our results call for a broader discussion within the scientific community, followed by discussions among risk assessors, policy makers, and other stakeholders as to whether or not the potential cancer risk levels that appear to be associated with currently derived HBGVs of NGXTCs are acceptable.

Integrating in vitro data and physiologically based kinetic (PBK) modelling to assess the in vivo potential developmental toxicity of a series of phenols.

Toxicity outcomes derived in vitro do not always reflect in vivo toxicity values, which was previously observed for a series of phenols tested in the embryonic stem cell test (EST). Translation of in vitro data to the in vivo situation is therefore an important, but still limiting step for the use of in vitro toxicity outcomes in the safety assessment of chemicals. The aim of the present study was to translate in vitro embryotoxicity data for a series of phenols to in vivo developmental toxic potency values for the rat by physiologically based kinetic (PBK) modelling-based reverse dosimetry. To this purpose, PBK models were developed for each of the phenols. The models were parameterised with in vitro-derived values defining metabolism and transport of the compounds across the intestinal and placental barrier and with in silico predictions and data from the literature. Using PBK-based reverse dosimetry, in vitro concentration-response curves from the EST were translated into in vivo dose-response curves from which points of departure (PoDs) were derived. The predicted PoDs differed less than 3.6-fold from PoDs derived from in vivo toxicity data for the phenols available in the literature. Moreover, the in vitro PBK-based reverse dosimetry approach could overcome the large disparity that was observed previously between the in vitro and the in vivo relative potency of the series of phenols. In conclusion, this study shows another proof-of-principle that the in vitro PBK approach is a promising strategy for non-animal-based safety assessment of chemicals.

The Isolated Chicken Eye test to replace the Draize test in rabbits.

In 1944, Draize et al., published a paper entitled "Methods for the study of irritation and toxicity of substances applied topically to the skin and mucous membranes". The Organization for Economic Co-operation and Development published their first guideline on eye irritation in 1981, using rabbits. In the early eighties the development of alternative non-animal tests to replace the Draize eye test started. The first attempts to validate alternative tests for eye irritation were considered to be relatively simple by comparing in vitro and in vivo irritation index scores. In the early nineteen-eighties, we introduced the use of isolated eyes as an alternative test for the Draize eye irritation test. What was expected to be a process of several years, however, turned out to be a decades spanning process still not fully completed. For a large part, this can be attributed to the nature of the in vivo test in rabbits, which is more complicated and compromised than originally believed. This paper describes, most chronologically, the development, performance, validation and application of the Isolated Eye Test and, in broader perspective, the international validation and acceptance of this alternative test by regulatory authorities and agencies.

An integrative test strategy for cancer hazard identification.

Assessment of genotoxic and carcinogenic potential is considered one of the basic requirements when evaluating possible human health risks associated with exposure to chemicals. Test strategies currently in place focus primarily on identifying genotoxic potential due to the strong association between the accumulation of genetic damage and cancer. Using genotoxicity assays to predict carcinogenic potential has the significant drawback that risks from non-genotoxic carcinogens remain largely undetected unless carcinogenicity studies are performed. Furthermore, test systems already developed to reduce animal use are not easily accepted and implemented by either industries or regulators. This manuscript reviews the test methods for cancer hazard identification that have been adopted by the regulatory authorities, and discusses the most promising alternative methods that have been developed to date. Based on these findings, a generally applicable tiered test strategy is proposed that can be considered capable of detecting both genotoxic as well as non-genotoxic carcinogens and will improve understanding of the underlying mode of action. Finally, strengths and weaknesses of this new integrative test strategy for cancer hazard identification are presented.

Prediction of carcinogenic potential of chemicals using repeated-dose (13-week) toxicity data.

Sub-chronic toxicity studies of 163 non-genotoxic chemicals were evaluated in order to predict the tumour outcome of 24-month rat carcinogenicity studies obtained from the EFSA and ToxRef databases. Hundred eleven of the 148 chemicals that did not induce putative preneoplastic lesions in the sub-chronic study also did not induce tumours in the carcinogenicity study (True Negatives). Cellular hypertrophy appeared to be an unreliable predictor of carcinogenicity. The negative predictivity, the measure of the compounds evaluated that did not show any putative preneoplastic lesion in de sub-chronic studies and were negative in the carcinogenicity studies, was 75%, whereas the sensitivity, a measure of the sub-chronic study to predict a positive carcinogenicity outcome was only 5%. The specificity, the accuracy of the sub-chronic study to correctly identify non-carcinogens was 90%. When the chemicals which induced tumours generally considered not relevant for humans (33 out of 37 False Negatives) are classified as True Negatives, the negative predictivity amounts to 97%. Overall, the results of this retrospective study support the concept that chemicals showing no histopathological risk factors for neoplasia in a sub-chronic study in rats may be considered non-carcinogenic and do not require further testing in a carcinogenicity study.

Predicting individual responses to pravastatin using a physiologically based kinetic model for plasma cholesterol concentrations.

We used a previously developed physiologically based kinetic (PBK) model to analyze the effect of individual variations in metabolism and transport of cholesterol on pravastatin response. The PBK model is based on kinetic expressions for 21 reactions that interconnect eight different body cholesterol pools including plasma HDL and non-HDL cholesterol. A pravastatin pharmacokinetic model was constructed and the simulated hepatic pravastatin concentration was used to modulate the reaction rate constant of hepatic free cholesterol synthesis in the PBK model. The integrated model was then used to predict plasma cholesterol concentrations as a function of pravastatin dose. Predicted versus observed values at 40 mg/d pravastatin were 15 versus 22 % reduction of total plasma cholesterol, and 10 versus 5.6 % increase of HDL cholesterol. A population of 7,609 virtual subjects was generated using a Monte Carlo approach, and the response to a 40 mg/d pravastatin dose was simulated for each subject. Linear regression analysis of the pravastatin response in this virtual population showed that hepatic and peripheral cholesterol synthesis had the largest regression coefficients for the non-HDL-C response. However, the modeling also showed that these processes alone did not suffice to predict non-HDL-C response to pravastatin, contradicting the hypothesis that people with high cholesterol synthesis rates are good statin responders. In conclusion, we have developed a PBK model that is able to accurately describe the effect of pravastatin treatment on plasma cholesterol concentrations and can be used to provide insight in the mechanisms behind individual variation in statin response.

Risk assessment of feed components of botanical origin - Approaches taken in the European Union.

In view of a continuous trend in replacing synthetic feed additives and especially flavouring compounds by botanical preparations, different aspects of the safety evaluations of plants and plant-derived preparations and components in feed are discussed. This includes risk assessment approaches developed by the European Food Safety Authority (EFSA) for phytotoxins regarding unintentional exposure of target animals and of consumers to animal derived food via carry-over from feed. Relevant regulatory frameworks for feed additives and feed contaminants in the European Union are summarised and the essentials of existing guidelines used in the safety evaluation of botanicals and their preparations and components in feed are outlined. The examples presented illustrate how the safety of the botanicals, their preparations and components present in feed is assessed. An outlook on possible future developments in risk assessment by applying new in vitro and in silico methodologies is given.

Safety of feed additives consisting of microcrystalline cellulose and carboxymethyl cellulose for all animal species (International Cellulosics Association).

Following a request from the European Commission, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety of microcrystalline cellulose and carboxymethyl cellulose as technological feed additives for all animal species. In its previous opinions on the safety and efficacy of the products, the FEEDAP Panel could not conclude on proper identification and characterisation as required for a feed additive. The occurrence of potential toxic impurities could also not be assessed. Based on the new data provided, the feed additives microcrystalline cellulose and carboxymethyl cellulose were properly identified and characterised and were shown to meet the specifications set for their use as food additives. Therefore, the conclusions of the safety reached in the previous opinions for microcrystalline cellulose and carboxymethyl cellulose meeting the food additive specifications apply to the microcrystalline cellulose and carboxymethyl cellulose under assessment as feed additives. The additives are considered safe for all animal species, the consumer and the environment. In the absence of data, the FEEDAP Panel is not in the position to conclude on the safety for the user.

Safety and efficacy of a feed additive consisting of Enterococcus lactis NCIMB 11181 (Lactiferm®) for chickens for fattening or reared for laying, other poultry species for fattening or reared for laying, and ornamental birds (Chr. Hansen A/S).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of a feed additive consisting of Enterococcus lactis NCIMB 11181 (Lactiferm®) as a zootechnical additive (gut flora stabiliser) for chickens for fattening, chickens reared for laying, other poultry species for fattening or reared for laying, and ornamental birds. The additive is available in two formulations: Lactiferm WS200 and Lactiferm Basic 50. The FEEDAP Panel concluded that the use of the additive is safe for chickens for fattening or reared for laying, other poultry species for fattening or reared for laying, and ornamental birds. The Panel also concluded that the use of the feed additive is safe for consumers, and the environment. Lactiferm WS200 is not irritant to skin or eyes. Owing to the proteinaceous nature of the active agent, both formulations of the additive are considered respiratory sensitisers. It was not possible, however, to conclude on the irritancy potential for skin and eyes of the Lactiferm Basic 50 formulation or on the potential of both formulations of the additive to cause skin sensitisation. The efficacy studies submitted did not allow to draw a conclusion on the efficacy of the additive for the target species. Lactiferm® is considered compatible with the coccidiostats monensin sodium and decoquinate.

Safety and efficacy of a feed additive consisting of Bacillus velezensis ATCC PTA-6737 (PB6) for the renewal of the authorisations in weaned piglets, weaned minor porcine species and sows and the extension of use to all Suidae (Kemin Europe N.V).

Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on Bacillus velezensis ATCC PTA-6737 as a zootechnical additive (functional group: gut flora stabilisers) in regard to the renewal of the authorisation for weaned piglets, weaned minor porcine species, sows and minor reproductive Suidae species, and its extension of use for all Suidae. The applicant provided evidence that the additive currently in the market complies with the conditions of the authorisation. The Panel concluded that there is no new evidence that would lead it to reconsider the previous conclusions; the additive is safe for the target species, consumers and the environment under the authorised conditions of use. This conclusion also applies to the target species/categories for which a request for an extension of use is made. The Panel concluded that B. velezensis ATCC PTA-6737 is not irritant to skin or eyes but should be considered a respiratory sensitiser due to its proteinaceous nature. No conclusions could be drawn on the skin sensitisation potential of the additive. The Panel concluded that the additive has the potential to be efficacious in all growing Suidae (suckling, weaned and fattening Suidae) at the minimum inclusion level of 1 × 107 CFU/kg of complete feed and in sows and minor reproductive Suidae species at 1 × 108 CFU/kg complete feed.

Safety for the user of the feed additive consisting of ferric tyrosine chelate (TYFER™) for chickens, turkeys and minor poultry species for fattening or reared for laying/breeding (Akeso Biomedical, Inc).

Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP Panel) was asked to deliver a scientific opinion on the safety for the users of the feed additive consisting of ferric tyrosine chelate (TYFER™) when used as a zootechnical additive for chickens, turkeys and minor poultry species for fattening or reared for laying/breeding. The European Commission request follows a previous opinion of the FEEDAP Panel. In that opinion, the Panel identified several risks for the users of the additive; it was listed that it posed a risk to users by inhalation, should be considered as an irritant to skin, eyes and mucous membranes, and also that, due to its nickel content, should be considered as a dermal and respiratory sensitiser. In the current application, the applicant proposed a maximum content of nickel (50 mg/kg). No changes in the manufacturing process have been reported by the applicant. In the absence of new data, the FEEDAP Panel reiterates its previous conclusion that the additive should be as an irritant to skin, eyes and mucous membranes and as a dermal and respiratory sensitiser.

Safety and efficacy of a feed additive consisting of a tincture derived from the roots of Panax ginseng C.A.Mey. (ginseng tincture) for horses, dogs and cats (FEFANA asbl).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of a tincture from the roots of Panax ginseng C.A.Mey. (ginseng tincture), when used as a sensory additive in feed for horses, dogs and cats. The product is a water/ethanol (40:60 v/v) solution, with a dry matter content of no more than 6% and a content of 0.01%-0.5% (w/w) for the sum of the two triterpene saponins ginsenoside Rb1 and ginsenoside Rg1. The Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that the tincture is safe for horses, dogs and cats at the maximum proposed use level of 48.6, 228.7 and 162 mg/kg complete feed, respectively. The Panel also concluded that the additive is considered safe for consumers when used at the proposed conditions of use in feed for horses. Ginseng tincture should be considered as an irritant to skin and eyes, and as a dermal and respiratory sensitiser. The use of the ginseng tincture as a flavour in feed for horses was not expected to pose a risk for the environment. Since the roots of P. ginseng and its preparations were recognised to flavour food and their function in feed would be essentially the same, no demonstration of efficacy was considered necessary.

Assessment of the feed additive consisting of Pediococcus pentosaceus DSM 14021 for all animal species for the renewal of its authorisation (Chr. Hansen A/S).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the assessment of the application for renewal of Pediococcus pentosaceus DSM 14021, a technological additive for all animal species. The applicant has provided evidence that the additive currently on the market complies with the existing conditions of authorisation. The Panel concluded that the additive remains safe for all animal species, consumers and the environment under the authorised conditions of use. Regarding user safety, the Panel considers that any exposure through skin and respiratory tract is considered a risk. The Panel cannot conclude on the eye irritation potential of the additive due to the lack of data. There is no need for assessing the efficacy of the additive in the context of the renewal of the authorisation.

Assessment of the feed additive consisting of Patent Blue V for all non-food-producing animal species for the renewal of its authorisation (Versele-Laga NV).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of Patent Blue V as a sensory feed additive for non-food-producing animals. The additive is already authorised for use with non-food-producing animals. The applicant has not provided evidence that the additive currently on the market complies with the existing conditions of authorisation. The FEEDAP Panel cannot conclude whether the additive remains safe for the target species due to the non-compliance with the specifications and the lack of adequate data on the potential aneugenicity of the additive. In the absence of data, the FEEDAP Panel cannot conclude on the potential of the additive to be a dermal and eye irritant nor a dermal and respiratory sensitiser. Since the potential genotoxicity of the additive was not ruled out, the exposure to the additive of the unprotected users should be minimised. The Panel retains that the previously made conclusion on the efficacy remains valid.

Safety and efficacy of a feed additive consisting of l-isoleucine produced with Corynebacterium glutamicum CGMCC 20437 for all animal species (Eppen Europe SAS).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of l-isoleucine produced by fermentation with Corynebacterium glutamicum CGMCC 20437 as a nutritional feed additive for use in feed and in water for drinking for all animal species. The production strain is non-genetically modified, qualifies for the QPS approach to safety assessment when used for production purposes, is susceptible to the relevant antibiotics and contains no antimicrobial resistance genes of concern. No viable cells of the production strain were detected in the final product. The additive does not give rise to any safety concern regarding the production strain. l-Isoleucine produced by fermentation with Corynebacterium glutamicum CGMCC 20437 is considered safe for the target species, the consumer and the environment. Regarding the use in water, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) reiterates its concerns over the safety for the target species of l-isoleucine administered simultaneously via water for drinking and feed owing to the risk of nutritional imbalances and hygienic reasons. In the absence of data, the FEEDAP Panel is not in a position to conclude on the potential of l-isoleucine produced by fermentation with Corynebacterium glutamicum CGMCC 20437 to be irritant to skin and/or eyes, or as a dermal sensitiser. Due to the high dusting potential, exposure by inhalation is likely. l-Isoleucine produced by fermentation with Corynebacterium glutamicum CGMCC 20437 is considered as an efficacious source of the essential amino acid l-isoleucine for non-ruminant animal species. For the supplemental l-isoleucine to be as efficacious in ruminants as in non-ruminant species, it would require protection against degradation in the rumen.

Efficacy of a feed additive consisting of endo-1,4-beta-xylanase and endo-1,3(4)-beta-glucanase produced with Talaromyces versatilis IMI 378536 and DSM 26702 (ROVABIO® ADVANCE) for weaned piglets (Adisseo France SAS).

Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the efficacy of ROVABIO® ADVANCE (liquid and solid) which contains endo-1,4-beta-xylanase and endo-1,3(4)-beta-glucanase produced with Talaromyces versatilis IMI 378536 and DSM 26702 as a zootechnical feed additive for weaned piglets at the recommended use level of 1800 U xylanase and 1250 U glucanase per kg feed. In a previous assessment, three long-term trials in weaned piglets were submitted. Two of them were considered to support the efficacy of the additive while a third trial was not further considered due to the large number of veterinary treatments applied. A new trial was provided to support the efficacy of the additive, but it did not show a significant improvement of the performance parameters at the minimum recommended use level. Due to the lack of sufficient data, the FEEDAP Panel is not in the position to conclude on the efficacy of the additive for the target species.

Safety of the feed additive consisting of endo-1,4-ß-xylanase (produced with Trichoderma reesei CBS 143953), subtilisin (produced with Bacillus subtilis CBS 143946) and α-amylase (produced with Bacillus amyloliquefaciens CBS 143954) (Avizyme® 1505) for all poultry species (Danisco (UK) Ltd.).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety of the feed additive consisting of endo-1,4-ß-xylanase (produced with Trichoderma reesei CBS 143953), subtilisin (produced with Bacillus subtilis CBS 143946) and α-amylase (produced with Bacillus amyloliquefaciens CBS 143954) (Avizyme® 1505) as a zootechnical feed additive for all poultry species. The additive is authorised in feed for chickens and turkeys for fattening, ducks and laying hens. In 2020, the FEEDAP Panel issued an opinion for the renewal of the authorisation of the additive for the species/categories for which there is an authorisation, a reduction of the minimum recommended level in turkeys for fattening and the extension of use to all poultry species. In that assessment, the Panel could not conclude on the safety of the additive due to uncertainties on the characterisation of the production strains and the possible presence of their viable cells and DNA in the final product. Moreover, limitations were identified in the xylanase specifications and xylanase method of analysis. The applicant submitted information to address the limitations previously identified. The Panel concluded that the additive is safe for the target species under the proposed conditions of use. The use of Avizyme® 1505 in animal nutrition is considered safe for the consumer and the environment. The additive is a mild irritant to skin and eyes; it is not a dermal sensitiser but should be considered a respiratory sensitiser. The additive is efficacious in ducks at 75 U endo-1,4-ß-xylanase, 1000 U subtilisin and 100 U α-amylase/kg of complete feed. In other poultry species for fattening (including turkeys), reared for breeding and reared for laying, the additive is efficacious at 187.5 U endo-1,4-ß-xylanase, 2500 U subtilisin and 250 U α-amylase per kg of complete feed and at 300 U endo-1,4-ß-xylanase, 4000 U subtilisin and 400 U α-amylase per kg of complete feed for all poultry species for laying (except for ducks).

Safety and efficacy of a feed additive consisting of a tincture derived from the flowers of Syzygium aromaticum (L.) Merr. & L.M. Perry (clove tincture) for all animal species (FEFANA asbl).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of a tincture from the dried flower bud of Syzygium aromaticum (L.) Merr. & L.M. Perry (clove tincture) when used as a sensory additive in feed and water for drinking for all animal species. The product is a ■■■■■) solution, with a dry matter content of ~ 1.66%. The product contains on average 0.511% phenolic acids (of which 0.0344% were flavonoids), 0.039% eugenol, 0.00019% methyleugenol and 0.00008% estragole. The Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that the use of clove tincture is very unlikely to be of safety concern for the target species up to the maximum proposed use level of 50 mg clove tincture/kg complete feed for all animal species, except for horses, for which the proposed use level is 200 mg/kg complete feed. The FEEDAP Panel considers that the use in water for drinking alone or in combination with use in feed should not exceed the daily amount that is considered very unlikely to be of safety concern when consumed via feed alone. No safety concern would arise for the consumer and the environment from the use of clove tincture up to the maximum proposed use levels in feed. The additive under assessment should be considered as irritant to skin and eyes, and as a dermal and respiratory sensitiser. When handling the additive, exposure of unprotected users to methyleugenol and estragole may occur. Therefore, to reduce the risk, the exposure of the users should be minimised. Since the flower buds of S. aromaticum and their preparations were recognised to flavour food and their function in feed would be essentially the same, no demonstration of efficacy was considered necessary.