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Schnuch A, Lessmann H, Becker D, Diepgen TL, Drexler H, Erdmann S, Fartasch M, Greim H, Kricke-Helling P, Merget R, Merk H, Nowak D, Rothe A, Stropp G, Wallenstein G, Uter W. Designation of substances as skin sensitizing chemicals: a reply. Hum Exp Toxicol 2016; 24:157-9. [PMID: 15901055 DOI: 10.1191/0960327105ht512xx] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Kemmerling J, Fehlert E, Kuper CF, Rühl-Fehlert C, Stropp G, Vogels J, Krul C, Vohr HW. The transferability from rat subacute 4-week oral toxicity study to translational research exemplified by two pharmaceutical immunosuppressants and two environmental pollutants with immunomodulating properties. Eur J Pharmacol 2015; 759:326-42. [PMID: 25823813 DOI: 10.1016/j.ejphar.2015.03.032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 03/05/2015] [Accepted: 03/12/2015] [Indexed: 01/29/2023]
Abstract
Exposure to chemicals may have an influence on the immune system. Often, this is an unwanted effect but in some pharmaceuticals, it is the intended mechanism of action. Immune function tests and in depth histopathological investigations of immune organs were integrated in rodent toxicity studies performed according to an extended OECD test guideline 407 protocol. Exemplified by two immunosuppressive drugs, azathioprine and cyclosporine A, and two environmental chemicals, hexachlorobenzene and benzo[a]pyrene, results of subacute rat studies were compared to knowledge in other species particular in humans. Although immune function has a high concordance in mammalian species, regarding the transferability from rodents to humans various factors have to be taken into account. In rats, sensitivity seems to depend on factors such as strain, sex, stress levels as well as metabolism. The two immunosuppressive drugs showed a high similarity of effects in animals and humans as the immune system was the most sensitive target in both. Hexachlorobenzene gave an inconsistent pattern of effects when considering the immune system of different species. In some species pronounced inflammation was observed, whereas in primates liver toxicity seemed more obvious. Generally, the immune system was not the most sensitive target in hexachlorobenzene-treatment. Immune function tests in rats gave evidence of a reaction to systemic inflammation rather than a direct impact on immune cells. Data from humans are likewise equivocal. In the case of benzo[a]pyrene, the immune system was the most sensitive target in rats. In the in vitro plaque forming cell assay (Mishell-Dutton culture) a direct comparison of cells from different species including rat and human was possible and showed similar reactions. The doses in the rat study had, however, no realistic relation to human exposure, which occurs exclusively in mixtures and in a much lower range. In summary, a case by case approach is necessary when testing immunotoxicity. Improvements for the translation from animals to humans related to immune cells can be expected from in vitro tests which offer direct comparison with reactions of human immune cells. This may lead to a better understanding of results and variations seen in animal studies.
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Affiliation(s)
- Jessica Kemmerling
- Bayer Pharma AG, GDD-GED-TOX-IT-Immunotoxicology, Aprather Weg, 42096 Wuppertal, Germany.
| | - Ellen Fehlert
- Department of Medicine IV, Eberhard-Karls University, Otfried-Müller Street 10, 72076 Tübingen, Germany
| | - C Frieke Kuper
- TNO Innovation for Life, PO Box 360, 3700 AJ Zeist, The Netherlands
| | | | - Gisela Stropp
- Bayer Pharma AG, GDD-GED-Product Stewardship Industrial Chemicals, Aprather Weg, 42096 Wuppertal, Germany
| | - Jack Vogels
- TNO Innovation for Life, PO Box 360, 3700 AJ Zeist, The Netherlands
| | - Cyrille Krul
- TNO Innovation for Life, PO Box 360, 3700 AJ Zeist, The Netherlands
| | - Hans-Werner Vohr
- Bayer Pharma AG, GDD-GED-TOX-IT-Immunotoxicology, Aprather Weg, 42096 Wuppertal, Germany
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Brüning T, Bartsch R, Bolt HM, Desel H, Drexler H, Gundert-Remy U, Hartwig A, Jäckh R, Leibold E, Pallapies D, Rettenmeier AW, Schlüter G, Stropp G, Sucker K, Triebig G, Westphal G, van Thriel C. Sensory irritation as a basis for setting occupational exposure limits. Arch Toxicol 2014; 88:1855-79. [PMID: 25182421 PMCID: PMC4161939 DOI: 10.1007/s00204-014-1346-z] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 07/21/2014] [Indexed: 02/06/2023]
Abstract
There is a need of guidance on how local irritancy data should be incorporated into risk assessment procedures, particularly with respect to the derivation of occupational exposure limits (OELs). Therefore, a board of experts from German committees in charge of the derivation of OELs discussed the major challenges of this particular end point for regulatory toxicology. As a result, this overview deals with the question of integrating results of local toxicity at the eyes and the upper respiratory tract (URT). Part 1 describes the morphology and physiology of the relevant target sites, i.e., the outer eye, nasal cavity, and larynx/pharynx in humans. Special emphasis is placed on sensory innervation, species differences between humans and rodents, and possible effects of obnoxious odor in humans. Based on this physiological basis, Part 2 describes a conceptual model for the causation of adverse health effects at these targets that is composed of two pathways. The first, “sensory irritation” pathway is initiated by the interaction of local irritants with receptors of the nervous system (e.g., trigeminal nerve endings) and a downstream cascade of reflexes and defense mechanisms (e.g., eyeblinks, coughing). While the first stages of this pathway are thought to be completely reversible, high or prolonged exposure can lead to neurogenic inflammation and subsequently tissue damage. The second, “tissue irritation” pathway starts with the interaction of the local irritant with the epithelial cell layers of the eyes and the URT. Adaptive changes are the first response on that pathway followed by inflammation and irreversible damages. Regardless of these initial steps, at high concentrations and prolonged exposures, the two pathways converge to the adverse effect of morphologically and biochemically ascertainable changes. Experimental exposure studies with human volunteers provide the empirical basis for effects along the sensory irritation pathway and thus, “sensory NOAEChuman” can be derived. In contrast, inhalation studies with rodents investigate the second pathway that yields an “irritative NOAECanimal.” Usually the data for both pathways is not available and extrapolation across species is necessary. Part 3 comprises an empirical approach for the derivation of a default factor for interspecies differences. Therefore, from those substances under discussion in German scientific and regulatory bodies, 19 substances were identified known to be human irritants with available human and animal data. The evaluation started with three substances: ethyl acrylate, formaldehyde, and methyl methacrylate. For these substances, appropriate chronic animal and a controlled human exposure studies were available. The comparison of the sensory NOAEChuman with the irritative NOAECanimal (chronic) resulted in an interspecies extrapolation factor (iEF) of 3 for extrapolating animal data concerning local sensory irritating effects. The adequacy of this iEF was confirmed by its application to additional substances with lower data density (acetaldehyde, ammonia, n-butyl acetate, hydrogen sulfide, and 2-ethylhexanol). Thus, extrapolating from animal studies, an iEF of 3 should be applied for local sensory irritants without reliable human data, unless individual data argue for a substance-specific approach.
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Affiliation(s)
- Thomas Brüning
- Institute for Prevention and Occupational Medicine of the German Social Accident Insurance (IPA), Bochum, Germany,
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Uter W, Stropp G, Schnuch A, Lessmann H. Aniline--a 'historical' contact allergen? Current data from the IVDK and review of the literature. ACTA ACUST UNITED AC 2006; 51:219-26. [PMID: 17135213 DOI: 10.1093/annhyg/mel076] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVES To assess whether aniline should be regarded as potential cause of contact allergy (CA). METHODS Retrospective analysis of clinical data collected in a CA surveillance network (IVDK, www.ivdk.org) between 01/1992 and 06/2004 and review of pertinent literature. RESULTS In the above period, 25 of the 1119 patients patch tested with aniline had positive (allergic) reactions; in 24 of these 25 patients, CA to p-phenylenediamine, p-aminoazobenzene or (in one case) another para-amino compound was additionally diagnosed. Exposure to aniline could not be ascertained in any of the cases, based on the available data. DISCUSSION Previous clinical results, which have been summarized and tabulated, are partly difficult to evaluate, as they may lack detail, or test concentrations are higher than those currently recommended, possibly yielding false-positive reactions. In none of the studies had previous exposures to aniline been unequivocally identified. CONCLUSION Based on clinical data it is unlikely that aniline is an independent sensitizer of current importance. However, it may elicit allergic reactions in subjects pre-sensitized to para-substituted amino compounds. In summary, supported by recent experimental evidence employing the local lymph node assay as a validated animal test system, it appears probable that aniline is a weak allergen.
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Affiliation(s)
- Wolfgang Uter
- Department of Medical Informatics, Biometry and Epidemiology, Friedrich-Alexander University Erlangen-Nürnberg Erlangen, Germany.
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Schlede E, Genschow E, Spielmann H, Stropp G, Kayser D. Oral acute toxic class method: A successful alternative to the oral LD50 test. Regul Toxicol Pharmacol 2005; 42:15-23. [PMID: 15896439 DOI: 10.1016/j.yrtph.2004.12.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2004] [Revised: 12/09/2004] [Accepted: 12/10/2004] [Indexed: 11/22/2022]
Abstract
The oral acute toxic class method (ATC method) was developed as an alternative to replace the oral LD50 test. The ATC method is a sequential testing procedure using only three animals of one sex per step at any of the defined dose levels. Depending on the mortality rate three but never more than six animals are used per dose level. This approach results in the reduction of numbers of animals used in comparison to the LD50 test by 40-70%. The principle of the oral ATC method is based on the Probit model and it was first evaluated on a biometric basis before a national and subsequently an international ring study were conducted. The results demonstrated an excellent agreement between the toxicity and the animal numbers predicted biometrically and observed in the validation studies. The oral ATC method was adopted as an official test guideline by OECD in 1996 and was slightly amended in 2001. The ATC method has been successfully used in Germany and in 2003 >85% of all tests on acute oral toxicity testing was conducted as oral ATC tests. In member states of the European Union the ATC method is used in the range of 50% of all tests conducted. Meanwhile the oral LD50 test has been deleted by OECD, by the European Union and by the USA, making the use of alternatives to the oral LD50 test mandatory.
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Affiliation(s)
- Eva Schlede
- Federal Institute for Risk Assessment (BfR), Department of Assessment of Chemicals 14195 Berlin, Germany
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Schlede E, Aberer W, Fuchs T, Gerner I, Lessmann H, Maurer T, Rossbacher R, Stropp G, Wagner E, Kayser D. Chemical substances and contact allergy--244 substances ranked according to allergenic potency. Toxicology 2003; 193:219-59. [PMID: 14599761 DOI: 10.1016/s0300-483x(03)00266-x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
From 1985 to 2001 a group consisting of thirty experts including dermatologists from universities, representatives from the chemical industry and from regulatory authorities elaborated and consequently decided on the potency ranking of chemicals with contact allergenic properties. These chemicals were defined either as synthetic chemicals or as chemicals identified as ingredients in natural products. On 244 substances clinical and experimental data on humans and results of animal tests as documented in the scientific literature were carefully collected and evaluated. This careful evaluation and assessment of these chemicals clearly demonstrate that ranking of substances according to their allergenic potency is possible and justified. It was decided to rank the most potent contact allergens in Category A of substances having significant allergenic properties. Substances with a solid-based indication of a contact allergenic potential and substances with the capacity of cross-reactions were listed in Category B and substances with insignificant or questionable allergenic effects were listed in Category C. An assessment of these compiled data is published here. Three Appendices give a comprehensive overview of the 98 substances listed in Category A, the 77 substances listed in Category B and the 69 substances listed in Category C.
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Affiliation(s)
- E Schlede
- Federal Institute for Risk Assessment (BfR), Thielallee 88-92, Berlin D-14195, Germany.
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Vohr HW, Ahr H, Stropp G. 100 Bisphenol a showed no skin sensitizing or photoallergic potential in a modified local lymph node assay in mice. Toxicol Lett 2003. [DOI: 10.1016/s0378-4274(03)90099-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Schnuch A, Lessmann H, Schulz KH, Becker D, Diepgen TL, Drexler H, Erdmann S, Fartasch M, Greim H, Kricke-Helling P, Merget R, Merk H, Nowak D, Rothe A, Stropp G, Uter W, Wallenstein G. When should a substance be designated as sensitizing for the skin ('Sh') or for the airways ('Sa')? Hum Exp Toxicol 2002; 21:439-44. [PMID: 12412637 DOI: 10.1191/0960327102ht278oa] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
In the List of MAK and BAT Values compounds are designated with 'Sa' ('sensitizing for the airways') or 'Sh' ('sensitizing for the skin') if, according to scientific evidence, they are allergens. Mainly based on suggestions by a WHO working group and based on our own experience, extended criteria have been elaborated by the working group 'skin and allergy' of the Commission of the Deutsche Forschungsgemeinschaft for the Investigation of Health Hazards of Chemical Compounds in the Work Area, which are presented in this article. They serve as guidelines for deciding which substances have to be labelled 'Sa' and 'Sh', respectively, for the prevention of sensitization and subsequent allergic diseases in workers. Although in some special cases their strict application may not be deemed necessary or possible, the proposed new criteria should be used to make the procedure of classification of substances: 1) more rational, 2) more consistent, 3) more comprehensible, and 4) more transparent. This paper informs readers working scientifically or administratively in this field and invites a critical discussion of the issue.
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Affiliation(s)
- A Schnuch
- IVDK/Institut an der Universitat Göttingen, Germany.
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Schnuch A, Lessmann H, Schulz KH, Becker D, Diepgen TL, Drexler H, Erdmann S, Fartasch M, Greim H, Greim H, Kricke-Helling P, Merget R, Merk H, Nowak D, Rothe A, Stropp G, Uter W, Wallenstein G. ["When should a substance be designated as sensitizing for the skin ("sh") or for the airways ("sa")"?"]. Pneumologie 2002; 56:304-8. [PMID: 12089648 DOI: 10.1055/s-2002-30696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- A Schnuch
- Institut an der Universität Göttingen, vol Siegold, Göttingen, Germany
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Wiemann C, Berthold K, Heusener A, Krüger N, Seeberger A, Stropp G. Joint positive control testing in guinea pig skin sensitization tests. A harmonized approach. Regul Toxicol Pharmacol 2002; 35:14-22. [PMID: 11846632 DOI: 10.1006/rtph.2001.1503] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A scheme for the performance of positive control studies within a coordinated group of laboratories was proposed (joint positive control testing). The procedure has been described, as well as the first results of the validation phase of this joint positive control testing project. Adoption of this proposal within the participating six laboratories would lead to a reduction in the number of guinea pigs required for reliability and sensitivity checks from current approximate 12 studies per year down to 2 studies, i.e., 150-300 fewer animals per year. Another benefit would be the use of a harmonized, and therefore more comparable, method to perform guinea pig tests and interpret the data. In the validation phase of joint reading of the positive control studies, the congruency of reading could clearly be demonstrated. From the experience gained up to now, it was possible to draw the conclusion that a coordinated interlaboratory approach for positive control testing was fully acceptable and an improvement with regard to animal welfare.
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Affiliation(s)
- C Wiemann
- Department of Product Safety, BASF Aktiengesellschaft, Ludwigshafen, Germany
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Steiling W, Basketter D, Berthold K, Butler M, Garrigue JL, Kimber I, Lea L, Newsome C, Roggeband R, Stropp G, Waterman S, Wiemann C. Skin sensitisation testing--new perspectives and recommendations. Food Chem Toxicol 2001; 39:293-301. [PMID: 11295477 DOI: 10.1016/s0278-6915(00)00147-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Various methodological aspects of skin sensitisation testing have been explored, particularly in the context of animal welfare considerations and reliability and sensitivity of test methods. Recommendations are made for the conduct of current and proposed OECD skin sensitisation tests with respect to appropriate test configurations for the purposes of hazard identification and labelling, and the requirement for positive controls. Specifically, the following aspects of guinea pig sensitisation test methods have been addressed: (1) the number of test and control animals required; (2) the option of using joint positive controls between independent laboratories; (3) the choice of positive control chemicals; (4) the optimal conduct and interpretation of rechallenge; and (5) the requirement for pretreatment with sodium lauryl sulfate. In addition, the use of the murine local lymph node assay (LLNA) has been considered. A number of conclusions have been drawn and recommendations made as follows: In many instances, particularly with the conduct of the guinea pig maximisation test, it is acceptable to halve the number of test and control animals used. An optional scheme for the conduct of joint positive control studies within a co-ordinated group of laboratories is appropriate. Only one positive control chemical (alpha-hexyl cinnamic aldehyde) is necessary for the routine assessment of assay sensitivity. The proper conduct and interpretation of rechallenge can provide valuable information and confirmation of results in guinea pig sensitisation tests. Sodium lauryl sulfate should no longer be used as a pretreatment in the guinea pig maximisation test. The LLNA is a viable and complete alternative to traditional guinea pig test methods for the purposes of skin sensitisation hazard identification. These recommendations provide the opportunity for both animal welfare benefits and improved hazard identification.
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Affiliation(s)
- W Steiling
- Henkel KGaA, Henkelstrasse 67, D-40191, Düsseldorf, Germany
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Kimber I, Basketter DA, Berthold K, Butler M, Garrigue JL, Lea L, Newsome C, Roggeband R, Steiling W, Stropp G, Waterman S, Wiemann C. Skin sensitization testing in potency and risk assessment. Toxicol Sci 2001; 59:198-208. [PMID: 11158712 DOI: 10.1093/toxsci/59.2.198] [Citation(s) in RCA: 133] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The purpose of this article is to review, and make recommendations for, the use of relevant skin sensitization test methods, for the purposes of determination of relative potency and the threshold dose necessary for the induction of skin sensitization, and for risk assessment. In addressing the first area, the utility of three guinea pig tests (the guinea pig maximization test, the occluded patch test, and the open epicutaneous test) of the local lymph node assay (LLNA) and of human volunteer testing for the assessment of relative potency and identification of thresholds for sensitization were considered. The following conclusions were drawn. (1) Although attempts have been made to modify the guinea pig maximization test for the purposes of deriving dose-response relationships, this method is usually unsuitable for determination of relative sensitizing potency. (2) Guinea pig methods that do not require the use of adjuvant and which employ a relevant route of exposure (the occluded patch test and the open epicutaneous test) are more appropriate for the assessment of relative skin-sensitizing potency. (3) The LLNA is suitable for the determination of relative skin sensitizing potency, and the adaptation of this method for derivation of comparative criteria such as EC3 values (the estimated concentration of test chemical required to induce a stimulation index of 3 in the LLNA) provides an effective and quantitative basis for such measurements. (4) For all the methods identified above, potency is assessed relative to other chemical allergens of known skin sensitizing potential. The estimation of likely threshold concentrations is dependent upon the availability of suitable benchmark chemicals of known potency for human sensitization. (5) Human testing (and specifically, the Human Repeat Insult Patch Test) can provide information of value in confirming the absence of skin sensitizing activity of formulations and products under specific conditions of use and exposure. Based on the above, the following recommendations are made. (1) If results are already available from suitable guinea pig tests, then judicious interpretation of the data may provide information of value in assessing relative skin sensitizing potency. This option should be explored before other analyses are conducted. (2) The LLNA is the recommended method for new assessments of relative potency, and/or for the investigation of the influence of vehicle or formulation on skin sensitizing potency. (3) Whenever available, human skin sensitization data should be incorporated into an assessment of relative potency. With respect to risk assessment, the conclusion drawn is that all the available data on skin-sensitizing activity in animals and man should be integrated into the risk-assessment process. Appropriate interpretation of existing data from suitable guinea pig studies can provide valuable information with respect to potency, as the first step in the development of a risk assessment. However, for de novo investigations, the LLNA is the method favored for providing quantitative estimations of skin-sensitizing potency that are best suited to the risk assessment process. Finally, human testing is of value in the risk assessment process, but is performed only for the purposes of confirming product safety.
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Affiliation(s)
- I Kimber
- Zeneca Central Toxicology Laboratory, Alderley Park, Macclesfield, Cheshire SK10 4TJ, United Kingdom.
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Stropp G, Berthold K, Bury D, Heusener A, Kühlem C, Pittermann W. The relevance of rechallenges and pretreatment with sodium lauryl sulfate (SLS) in the guinea pig maximization test (GPMT) was evaluated. Food Chem Toxicol 1999; 37:266-8. [PMID: 10227747 DOI: 10.1016/s0278-6915(98)00123-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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