Report of an Expert Panel on the reanalysis by of a 90-day study conducted by Monsanto in support of the safety of a genetically modified corn variety (MON 863).

MON 863, a genetically engineered corn variety that contains the gene for modified Bacillus thuringiensis Cry3Bb1 protein to protect against corn rootworm, was tested in a 90-day toxicity study as part of the process to gain regulatory approval. This study was reanalyzed by Séralini et al. who contended that the study showed possible hepatorenal effects of MON 863. An Expert Panel was convened to assess the original study results as analyzed by the Monsanto Company and the reanalysis conducted by Séralini et al. The Expert Panel concludes that the Séralini et al. reanalysis provided no evidence to indicate that MON 863 was associated with adverse effects in the 90-day rat study. In each case, statistical findings reported by both Monsanto and Séralini et al. were considered to be unrelated to treatment or of no biological or clinical importance because they failed to demonstrate a dose-response relationship, reproducibility over time, association with other relevant changes (e.g., histopathology), occurrence in both sexes, difference outside the normal range of variation, or biological plausibility with respect to cause-and-effect. The Séralini et al. reanalysis does not advance any new scientific data to indicate that MON 863 caused adverse effects in the 90-day rat study.

Comments on the Environmental Protection Agency's definition of risk assessment.

Common sense requires that regulation to prevent the adverse effects of exposure to chemicals should when possible preserve the desirable or beneficial effects of exposure to the chemical. Excluding such effects by definition is contrary to good science and common sense.

Human exposure to dioxins from food, 1999-2002.

In response to aggressive attempts to control dioxin emissions over the last 35 years, human exposures to dioxins from the environment have declined significantly. The primary source of human exposure to dioxins at present is food. The sources of dioxins in food are not well understood and are probably varied. Data on the levels of dioxins measured in various foods for samples collected from 2000 to 2002 have recently been released by the US Food and Drug Administration as part of its Total Diet Study. Data on samples collected in 1999, and released in 2002, are also available. Based on those data and on the US Department of Agriculture's most recent food consumption survey (1994-1996 & 1998 Continuing Survey of Food Intakes by Individuals), estimates of dioxin intake for the total US population and for three age groups of children were obtained. Results show that the most recent mean dietary exposures for all groups are below 2 pg TEQ/kg BW/day, the tolerable daily intake established for dioxins by the World Health Organization. Between 1999 and 2002 mean dioxin intakes from food appear to have decreased, but when estimates are adjusted based on a standardized limit of detection and evaluating only those {congenerxfood} combinations common to all 4 years, no trend is apparent. When dioxin concentrations below the limit of detection are represented by one-half the limit, approximately 5% of the intake estimates for 2-year-olds and 1% of the intake estimates for 6-year-olds exceed the tolerable daily intake by about 10%, although such upper-percentile estimates should not be equated with excess risk. When non-detectable dioxin values are set to zero (i.e., when only dioxin values actually measured are used), only 1% of intake estimates exceed the tolerable daily intake for 2-year-olds. As expected, about 50% of daily dietary dioxin intake by the total US population is attributable to meat and dairy products, based on the same food group classifications used by the National Academy of Sciences' Committee on the Implications of Dioxin in the Food Supply. This information may be useful for targeting future risk management activities.

The FEMA GRAS assessment of phenethyl alcohol, aldehyde, acid, and related acetals and esters used as flavor ingredients.

This publication is the ninth in a series of safety evaluations performed by the Expert Panel of the Flavor and Extract Manufacturers Association (FEMA). In 1993, the Panel initiated a comprehensive program to re-evaluate the safety of more than 1700 GRAS flavoring substances under conditions of intended use. Elements that are fundamental to the safety evaluation of flavor ingredients include exposure, structural analogy, metabolism, pharmacokinetics and toxicology. Flavor ingredients are evaluated individually and in the context of the available scientific information on the group of structurally related substances. Scientific data relevant to the safety evaluation of the use of phenethyl alcohol, aldehyde, acid, and related acetals and esters as flavoring ingredients is evaluated. The group of phenethylalcohol, aldehyde, acid, and related acetals and esters was reaffirmed as GRAS (GRASr) based, in part, on their self-limiting properties as flavoring substances in food, their rapid absorption, metabolic detoxication, and excretion in humans and other animals, their low level of flavor use, the wide margins of safety between the conservative estimates of intake and the no-observed-adverse effect levels determined from subchronic and chronic studies and the lack of significant genotoxic and mutagenic potential. This evidence of safety is supported by the fact that the intake of phenethyl alcohol, aldehyde, acid, and related acetals and esters as natural components of traditional foods is greater than their intake as intentionally added flavoring substances.

The FEMA GRAS assessment of benzyl derivatives used as flavor ingredients.

This publication is the eighth in a series of safety evaluations performed by the Expert Panel of the Flavor and Extract Manufacturers Association (FEMA). In 1993, the panel initiated a comprehensive program to re-evaluate the safety of more than 1700 GRAS flavoring substances under conditions of intended use. Elements that are fundamental to the safety evaluation of flavor ingredients include exposure, structural analogy, metabolism, pharmacokinetics and toxicology. Flavor ingredients are evaluated individually and in the context of the available scientific information on the group of structurally related substances. Scientific data relevant to the safety evaluation of the use of benzyl derivatives as flavoring ingredients is evaluated. The group of benzyl derivatives was reaffirmed as GRAS (GRASr) based, in part, on their self-limiting properties as flavoring substances in food; their rapid absorption, metabolic detoxication, and excretion in humans and other animals, their low level of flavor use, the wide margins of safety between the conservative estimates of intake and the no-observed-adverse effect levels determined from subchronic and chronic studies and the lack of significant genotoxic and mutagenic potential. This evidence of safety is supported by the fact that the intake of benzyl derivatives as natural components of traditional foods is greater than their intake as intentionally added flavoring substances.

The FEMA GRAS assessment of hydroxy- and alkoxy-substituted benzyl derivatives used as flavor ingredients.

This publication is the ninth in a series of safety evaluations performed by the Expert Panel of the Flavor and Extract Manufacturers Association (FEMA). In 1993, the Panel initiated a comprehensive program to re-evaluate the safety of more than 1700 GRAS flavoring substances under conditions of intended use. Elements that are fundamental to the safety evaluation of flavor ingredients include exposure, structural analogy, metabolism, pharmacokinetics and toxicology. Flavor ingredients are evaluated individually and in the context of the available scientific information on the group of structurally related substances. Scientific data relevant to the safety evaluation of the use of hydroxy- and alkoxy-substituted benzyl derivatives as flavoring ingredients is evaluated. The group of hydroxy- and alkoxy-benzyl derivatives was reaffirmed as GRAS (GRASr) based, in part, on their self-limiting properties as flavoring substances in food; their rapid absorption, metabolic detoxication, and excretion in humans and other animals; their low level of flavor use; the wide margins of safety between the conservative estimates of intake and the no-observed-adverse effect levels determined from subchronic and chronic studies and the lack of significant genotoxic and mutagenic potential. This evidence of safety is supported by the fact that the intake of hydroxy- and alkoxy-substituted benzyl derivatives as natural components of traditional foods is greater than their intake as intentionally added flavoring substances.

A procedure for the safety evaluation of natural flavor complexes used as ingredients in food: essential oils.

A scientifically based guide has been developed to evaluate the safety of naturally occurring mixtures, particularly essential oils, for their intended use as flavor ingredients. The approach relies on the complete chemical characterization of the essential oil and the variability of the composition of the oil in the product intended for commerce. Being products of common plant biochemical pathways, the chemically identified constituents are organized according to a limited number of well-established chemical groups called congeneric groups. The safety of the intake of the each congeneric group from consumption of the essential oil is evaluated in the context of data on absorption, metabolism, and toxicology of members of the congeneric group. The intake of the group of unidentified constituents is evaluated in the context of the consumption of the essential oil as a food, a highly conservative toxicologic threshold, and toxicity data on the essential oil or an essential oil of similar chemotaxonomy. The flexibility of the guide is reflected in the fact that high intake of major congeneric groups of low toxicologic concern will be evaluated along with low intake of minor congeneric groups of significant toxicological concern (i.e., higher structural class). The guide also provides a comprehensive evaluation of all congeneric groups and constituents that account for the majority of the composition of the essential oil. The overall objective of the guide is to organize and prioritize the chemical constituents of an essential oil in order that no reasonably possible significant risk associated with the intake of essential oil goes unevaluated. The guide is, however, not intended to be a rigid checklist. The Flavor and Extract Manufacturers Association (FEMA) Expert Panel will continue to evaluate each essential oil on a case by case basis applying their scientific judgment to insure that each natural flavor complex is exhaustively evaluated.

Physiology of antibiotic production in actinomycetes and some underlying control mechanisms.

Some of the accumulated information on the physiology and nutritional control of antibiotic production in actinomycetes can now be related to recent discoveries in the field of actinomycete molecular biology. This review focuses on aspects of genetic and metabolic control of antibiotic biosynthesis. It surveys some well established principles in the relationship between primary and secondary metabolism, and summarizes briefly the areas where progress is being made in elucidating the molecular organization of regulatory systems underlying this relationship.

Culture conditions promoting dispersed growth and biphasic production of actinorhodin in shaken cultures of Streptomyces coelicolor A3(2).

Media and culture conditions were developed for experiments on the physiology of secondary metabolism in Streptomyces coelicolor A3(2). Well dispersed mycelial growth was obtained in a buffered starch-glutamate-salts medium; a high (5%) starch concentration and addition of glass beads aided dispersal. Under the conditions developed, production of actinorhodin was suppressed during trophophase growth and began abruptly near the growth maximum.

Paracelsus, Haber and Arndt.

After a brief overview of the contributions of Paracelsus, Haber and Arndt to the theory of toxicology, examples are provided for quantitative risk/safety assessments using dose (c), time (t) and effect (E) as macroscopic variables of toxicity. The discussion offers explanations for application of the decision tree approach in identifying rate-determining steps in the toxicity of chemicals. Having done so allows for reasonably accurate predictions of cancer incidence (bladder, liver, heart, histiocyte) using Haber's Product under isoeffective conditions and the equation cxt=kxE for isodosic and isotemporal responses.

Dose and time as variables of toxicity.

Recognizing that if there is no exposure, there is no toxicity leads us to the conclusion that if there is exposure, toxicity can ensue when exposure exceeds a certain dose and/or time and that it will be dependent on toxicokinetics and toxicodynamics. Analysis of the fundamental description of toxicity (dT/dE=dT/dDxdD/dKxdK/dE, where T stands for toxicity, D for toxicodynamics, K for toxicokinetics and E for exposure) yields the recognition of three independent time scales, the first being an intrinsic property of a given compound (what does the chemical do to the organism), which is the dynamic time scale. The second time scale is an intrinsic property of a the organism (what does the organism do to the chemical), which represents the kinetic time scale. The frequency of exposure denotes the third time scale, which is independent of the dynamic and kinetic time scales. Frequency of exposure depends on the experimental design or on nature, but not on the organism or substance. A liminal condition occurs when the frequency becomes so high that it is indistinguishable from continuous exposure. Continuous exposure forces the two other time scales to become synchronized thereby reducing complexity to three variables: dose, effect and one time scale. Keeping one of those variables constant allows for the study of the other two variables reproducibly under isoeffective or isodosic or isotemporal conditions. However, any departure from continuous exposure will introduce the full complexity of four independent variables (dose and kinetic, dynamic and frequency time scales) impacting on the effect (dependent variable) at the same time. The examples discussed in this paper demonstrate how nature in the form of long half-lives provides liminal conditions when either kinetic or dynamic half lives force synchronization of all three time scales. However, for compounds having very short dynamic or kinetic half-lives, only continuous exposure will provide a synchronized time scale. A decision tree-type approach is being used to illustrate how to reduce the enormous complexity generated by five variables (dose, effect and up to three time scales) in toxicology to manageable proportions by identifying and modeling the rate-determining (-limiting) step(s) in the manifestation of toxicity.

Occupational exposure limits for 30 organophosphate pesticides based on inhibition of red blood cell acetylcholinesterase.

Toxicity and other relevant data for 30 organophosphate pesticides were evaluated to suggest inhalation occupational exposure limits (OELs), and to support development of a risk assessment strategy for organophosphates in general. Specifically, the value of relative potency analysis and the predictability of inhalation OELs by acute toxicity measures and by repeated oral exposure NOELs was assessed. Suggested OELs are based on the prevention of red blood cell (RBC) acetylcholinesterase (AChE) inhibition and are derived using a weight-of-evidence risk assessment approach. Suggested OEL values range from 0.002 to 2 mg/m(3), and in most cases, are less than current permissible exposure levels (PELs) or threshold limit values(R) (TLVs(R)). The available data indicate that experimental data for most organophosphates evaluated are limited; most organophosphates are equally potent RBC AChE inhibitors in different mammalian species; NOELs from repeated exposure studies of variable duration are usually equivalent; and, no particular grouping based on organophosphate structure is consistently more potent than another. Further, relative potency analyses have limited usefulness in the risk assessment of organophosphates. The data also indicated that equivalent relative potency relationships do not exist across either exposure duration (acute vs. repeated) or exposure route (oral vs. inhalation). Consideration of all variable duration and exposure route studies are therefore usually desirable in the development of an OEL, especially when data are limited. Also, neither acute measures of toxicity nor repeated oral exposure NOELs are predictive of weight-of-evidence based inhalation OELs. These deviations from what is expected based on the common mechanism of action for organophosphates across exposure duration and route - AChE inhibition - is likely due to the lack of synchrony between the timing of target tissue effective dose and the experimental observation of equivalent response. Thus, comprehensive interpretation of all toxicity data in the context of available toxicokinetic, toxicodynamic and exposure information for each individual organophosphate in a weight-of-evidence based risk assessment is desirable when deriving inhalation OELs.

Relative potency of chlorinated dibenzo-p-dioxins (CDDs) in acute, subchronic and chronic (carcinogenicity) toxicity studies: implications for risk assessment of chemical mixtures.

This paper shows that the relative toxic potency of four chlorinated dibenzo-p-dioxins (CDDs) is similar in two species with different sensitivities (guinea pig, Sprague-Dawley rat). More importantly, it also demonstrates that the relative toxic potencies of these homologues are very similar for acute, subchronic and chronic dosing in the same species (rat). Furthermore, examination of different endpoints of toxicity (mortality, porphyria, carcinogenicity) suggests that the dose-responses for these diverse end-points after acute, subchronic, and chronic administration are very similar if not identical for tetra-CDD. Based on toxicokinetic and toxicodynamic considerations, a new, possibly generalizable rule (average tissue concentration x time = toxicity) is derived for CDDs. Implicit in the relative potency arguments of CDDs is the requirement of a practical threshold dose for all endpoints of toxicity including cancer.

Global estimates of acute pesticide morbidity and mortality.

Mathematical models have projected increasing numbers of pesticide poisoning throughout the world, rising from 500,000 cases/yr in 1972 to 25,000,000 cases/yr in a 1990 estimate. Among 148 outbreaks (excluding Bhopal and three probable epidemics of pesticide-related suicide) reported between 1951-90, the known number of cases was 24,731 with 1065 deaths (4.3% case fatality); these are probably underestimates. Among the known outbreaks, the most commonly identified agents were organophosphates (58), carbamates (23), chlorinated hydrocarbons (23), and organic mercurials (11). Food was the most common vehicle of exposure in these epidemics (83 outbreaks), followed by skin contact (26), multiple types of exposure (22), and respiratory exposure (16). Two countries, the United States and Thailand, accounted for more than half the reports. Both the mathematical models and the outbreak investigations support the need for continuing investigation and improved surveillance throughout the world.

Safety evaluation of natural flavour complexes.

Natural flavour complexes (NFCs) are chemical mixtures obtained by applying physical separation methods to botanical sources. Many NFCs are derived from foods. In the present paper, a 12-step procedure for the safety evaluation of NFCs, 'the naturals paradigm', is discussed. This procedure, which is not intended to be viewed as a rigid check list, begins with a description of the chemical composition of the commercial product, followed by a review of the data on the history of dietary use. Next, each constituent of an NFC is assigned to one of 33 congeneric groups of structurally related substances and to one of three classes of toxic potential, each with its own exposure threshold of toxicological concern. The group of substances of unknown structure is placed in the class of greatest toxic potential. In subsequent steps, for each congeneric group the procedure determines the per capita intake, considers metabolic pathways and explores the need and availability of toxicological data. Additional toxicological and analytical data may be required for a comprehensive safety evaluation. The procedure concludes with an evaluation of the NFC in its entirety, also considering combined exposure to congeneric groups. The first experiences with the use of this procedure are very promising. Future safety evaluations of larger numbers of NFCs will indicate the usefulness of the system, either in its present form or in a form modified on the basis of experience.

The FEMA GRAS assessment of furfural used as a flavour ingredient. Flavor and Extract Manufacturers' Association.

The Expert Panel of the Flavor and Extract Manufacturers' Association (FEMA) has assessed the safety of furfural for its continued use as a flavour ingredient. The safety assessment takes into account the current scientific information on exposure, metabolism, pharmacokinetics, toxicology, carcinogenicity and genotoxicity. Furfural was reaffirmed as GRAS (GRASr) as a flavour ingredient under conditions of intended use based on: (1) its mode of metabolic detoxication in humans; (2) its low level of flavour use compared with higher intake levels as a naturally occurring component of food; (3) the safety factor calculated from results of subchronic and chronic studies, (4) the lack of reactivity with DNA; and (5) the conclusion that the only statistically significant finding in the 2-year NTP bioassays, an increased incidence of hepatocellular adenomas and carcinomas in the high-dose group of male mice, was secondary to pronounced hepatotoxicity. Taken together, these data do not indicate any risk to human health under conditions of use as a flavour ingredient. This evidence of safety is supported by the occurrence of furfural as a natural component of traditional foods, at concentrations in the diet resulting in a 'natural intake' that is at least 100 times higher than the intake of furfural from use as a flavour ingredient.

The FEMA GRAS assessment of pyrazine derivatives used as flavor ingredients. Flavor and Extract Manufacturers Association.

This is the fifth in a series of safety evaluations performed by the Expert Panel of the Flavor and Extract Manufacturers Association (FEMA). In 1993, the Panel initiated a comprehensive program to re-evaluate the safety of more than 1700 GRAS flavoring substances under conditions of intended use. Elements that are fundamental to the safety evaluation of flavor ingredients include exposure, structural analogy, metabolism, pharmacokinetics and toxicology. Flavor ingredients are evaluated individually taking into account the available scientific information on the group of structurally related substances. Scientific data relevant to the safety evaluation of the use of pyrazine derivatives as flavoring ingredients is evaluated.

Safety assessment of allylalkoxybenzene derivatives used as flavouring substances - methyl eugenol and estragole.

This publication is the seventh in a series of safety evaluations performed by the Expert Panel of the Flavor and Extract Manufacturers' Association (FEMA). In 1993, the Panel initiated a comprehensive program to re-evaluate the safety of more than 1700 GRAS flavouring substances under conditions of intended use. In this review, scientific data relevant to the safety evaluation of the allylalkoxybenzene derivatives methyl eugenol and estragole is critically evaluated by the FEMA Expert Panel. The hazard determination uses a mechanism-based approach in which production of the hepatotoxic sulfate conjugate of the 1'-hydroxy metabolite is used to interpret the pathological changes observed in different species of laboratory rodents in chronic and subchronic studies. In the risk evaluation, the effect of dose and metabolic activation on the production of the 1'-hydroxy metabolite in humans and laboratory animals is compared to assess the risk to humans from use of methyl eugenol and estragole as naturally occurring components of a traditional diet and as added flavouring substances. Both the qualitative and quantitative aspects of the molecular disposition of methyl eugenol and estragole and their associated toxicological sequelae have been relatively well defined from mammalian studies. Several studies have clearly established that the profiles of metabolism, metabolic activation, and covalent binding are dose dependent and that the relative importance diminishes markedly at low levels of exposure (i.e. these events are not linear with respect to dose). In particular, rodent studies show that these events are minimal probably in the dose range of 1-10 mg/kg body weight, which is approximately 100-1000 times the anticipated human exposure to these substances. For these reasons it is concluded that present exposure to methyl eugenol and estragole resulting from consumption of food, mainly spices and added as such, does not pose a significant cancer risk. Nevertheless, further studies are needed to define both the nature and implications of the dose-response curve in rats at low levels of exposure to methyl eugenol and estragole.

The FEMA GRAS assessment of alicyclic substances used as flavour ingredients.

For over 35 years, an independent panel of expert scientists has served as the primary body for evaluating the safety of flavour ingredients. This group, the Expert Panel of the Flavor and Extract Manufacturers' Association (FEMA), has achieved international recognition from the flavour industry, government regulatory bodies including the Food and Drug Administration, and the toxicology community for its unique contributions. To date, the Expert Panel has evaluated the safety of more than 1700 flavour ingredients and determined the vast majority to be "generally recognized as safe" (GRAS). Elements that are fundamental to the safety evaluation of flavour ingredients include exposure, structural analogy, metabolism, pharmacokinetics and toxicology. Flavour ingredients are evaluated individually taking into account the available scientific information on the group of structurally related substances. The elements of the GRAS assessment program as they have been applied by the Expert Panel to the group of 119 alicyclic substances used as flavour ingredients, and the relevant scientific data which provide the basis for the GRAS status of these substances, are described herein.

The FEMA GRAS assessment of trans-anethole used as a flavouring substance. Flavour and Extract Manufacturer's Association.

This publication is the fourth in a series of safety evaluations performed by the Expert Panel of the Flavour and Extract Manufacturers' Association (FEMA). In 1993, the Panel initiated a comprehensive program to re-evaluate the safety of more than 1700 GRAS flavouring substances under conditions of intended use. In this review, scientific data relevant to the safety evaluation of trans-anethole (i.e. 4-methoxypropenylbenzene) as a flavouring substance is critically evaluated by the FEMA Expert Panel. The evaluation uses a mechanism-based approach in which production of the hepatotoxic metabolite anethole epoxide (AE) is used to interpret the pathological changes observed in different species and sexes of laboratory rodents in chronic and subchronic dietary studies. Female Sprague Dawley rats metabolize more trans-anethole to AE than mice or humans and, therefore, are the most conservative model for evaluating the potential for AE-induced hepatotoxicity in humans exposed to trans-anethole from use as a flavouring substance. At low levels of exposure, trans-anethole is efficiently detoxicated in rodents and humans primarily by O-demethylation and omega-oxidation, respectively, while epoxidation is only a minor pathway. At high dose levels in rats, particularly females, a metabolic shift occurs resulting in increased epoxidation and formation of AE. Lower activity of the "fast" acting detoxication enzyme epoxide hydrolase in the female is associated with more pronounced hepatotoxicity compared to that in the male. The continuous intake of high dose levels of trans-anethole (i.e. cumulative exposure) has been shown in dietary studies to induce a continuum of cytotoxicity, cell necrosis and cell proliferation. In chronic dietary studies in rats, hepatotoxicity was observed when the estimated daily hepatic production of AE exceeded 30 mg AE/kg body weight. In female rats, chronic hepatotoxicity and a low incidence of liver tumours were reported at a dietary intake of 550 mg trans-anethole/kg body weight/day. Under these conditions, daily hepatic production of AE exceeded 120 mg/kg body weight. Additionally, neither trans-anethole nor AE show any evidence of genotoxicity. Therefore, the weight of evidence supports the conclusion that hepatocarcinogenic effects in the female rat occur via a non-genotoxic mechanism and are secondary to hepatotoxicity caused by continuous exposure to high hepatocellular concentrations of AE. trans-Anethole was reaffirmed as GRAS (GRASr) based on (1) its low level of flavour intake (54 microg/kg body weight/day); (2) its metabolic detoxication pathway in humans at levels of exposure from use as a flavouring substance; (3) the lack of mutagenic or genotoxic potential; (4) the NOAEL of 120 mg trans-anethole/kg body weight/day in the female rat reported in a 2 + -year study which produces a level of AE (i.e. 22 mg AE/kg body weight/day) at least 10,000 times the level (0.002 mg AE/kg body weight day) produced from the intake of trans-anethole from use as a flavouring substance; and (5) the conclusion that a slight increase in the incidence of hepatocellular tumours in the high dose group (550 mg trans-anethole/kg body weight/day) of female rats was the only significant neoplastic finding in a 2+ -year dietary study. This finding is concluded to be secondary to hepatotoxicity induced by high hepatocellular concentrations of AE generated under conditions of the study. Because trans-anethole undergoes efficient metabolic detoxication in humans at low levels of exposure, the neoplastic effects in rats associated with dose-dependent hepatotoxicity are not indicative of any significant risk to human health from the use of trans-anethole as a flavouring substance.