Regulatory Toxicology and Pharmacology : RTP This is an RSS file. You can use it to subscribe to this data in your favourite RSS reader or to display this data on your own website or blog.

New supporting data to guide the use of evident toxicity in acute oral toxicity studies (OECD TG 420)
Regul Toxicol Pharmacol. 2023 Oct 12:105517. doi: 10.1016/j.yrtph.2023.105517. Online ahead of print.ABSTRACTCurrently there are three test guidelines (TG) for acute oral toxicity studies of substances or mixtures from the Organisation for Economic Co-operation and Development (OECD). TG 423 and TG 425 use lethality as an endpoint, while TG 420 replaces death with 'evident toxicity', defined as clear signs that exposure to a higher dose would result in death. However, the perceived subjectivity of 'evident toxicity' may be preventing wider use of TG 420. To address this, the UK National Centre for the Replacement, Refineme...
Source: Regulatory Toxicology and Pharmacology : RTP - October 14, 2023 Category: Toxicology Authors: Fiona Sewell Ian Ragan Graham Horgan David Andrew Thomas Holmes Irene Manou Boris P M üller Tim Rowan Barbara G Schmitt Marco Corvaro Source Type: research

Quantitative structure use relationships: Highlights from a technical summit meeting
Discussions also led to proposals for applications beyond exposure and risk modeling, including sustainable formulation discovery. In addition, discussions continue to construct, conduct, and circulate case studies tied to various specific problem formulations in which QSURs supply or derive information on chemical functions, concentrations, and exposures.PMID:37838348 | DOI:10.1016/j.yrtph.2023.105516 (Source: Regulatory Toxicology and Pharmacology : RTP)
Source: Regulatory Toxicology and Pharmacology : RTP - October 14, 2023 Category: Toxicology Authors: Rosemary T Zaleski Andreas Ahrens Jon A Arnot Richard A Becker Mark Bonnell Sean Collins Paul DeLeo Peter Egeghy Michelle Embry Todd Gouin Kristin Isaacs Elke Jensen Source Type: research

Biomonitoring Equivalents for N,N-Diethyl-meta-toluamide (DEET)
Regul Toxicol Pharmacol. 2023 Oct 12:105506. doi: 10.1016/j.yrtph.2023.105506. Online ahead of print.ABSTRACTN,N-Diethyl-meta-toluamide (DEET) is widely used as an effective mosquito and tick repellent. DEET is absorbed systemically after applications to skin. Once absorbed, DEET is rapidly metabolized with the predominant metabolite being m-dimethylaminocarbonyl benzoic acid (DBA). DEET and metabolites are predominantly excreted in urine after being absorbed systemically. Exposures to DEET are typically biomonitored via measures of DEET and DBA in urine. In this evaluation, we review available health-based risk assessment...
Source: Regulatory Toxicology and Pharmacology : RTP - October 14, 2023 Category: Toxicology Authors: Sean M Hays Christopher R Kirman Source Type: research

An international cross-laboratory survey on fish vitellogenin analysis: Methodological challenges and opportunities for best practice
Regul Toxicol Pharmacol. 2023 Oct 9:105501. doi: 10.1016/j.yrtph.2023.105501. Online ahead of print.ABSTRACTVitellogenin (VTG) is a biomarker for possible endocrine activity of chemicals acting via the estrogen, androgen, or steroidogenesis pathways. VTG is assessed in standardised fish guideline studies conducted for regulatory safety assessment of chemicals. VTG data can be highly variable leading to concerns for potential equivocal, false positive and/or negative outcomes. Consequently, additional fish testing may be required to address uncertainties in the VTG response, and possibly erroneous/missed identification of e...
Source: Regulatory Toxicology and Pharmacology : RTP - October 11, 2023 Category: Toxicology Authors: Natalie Burden Rebecca J Brown Breanne Holmes Grace H Panter Edward R Salinas Fiona Sewell Lennart Weltje James R Wheeler Yvonne Wolf Laurent Lagadic Source Type: research

A comparison between field measurements of vapour concentrations of plant protection products and predictions by the BROWSE model
Regul Toxicol Pharmacol. 2023 Oct 6:105504. doi: 10.1016/j.yrtph.2023.105504. Online ahead of print.ABSTRACTA database of field measurements of air concentrations of pesticide active ingredients has previously been compiled by CropLife Europe with an aim to revise the default air concentration values and assumptions applied in assessing vapour exposure in the risk assessment of bystanders and residents. The BROWSE model, released in 2014, which is a regulatory risk assessment model that includes the exposure of residents and bystanders has a component relating to post-application vapour inhalation. Predictions of concentra...
Source: Regulatory Toxicology and Pharmacology : RTP - October 8, 2023 Category: Toxicology Authors: M Clare Butler Ellis Edgars Felkers Sarah Adham Anne-Kim Vinck Kathrin B ürling Neil Morgan Source Type: research

Nitrosamine acceptable intakes should consider variation in molecular weight: The implication of stoichiometric DNA damage
Regul Toxicol Pharmacol. 2023 Oct 5:105505. doi: 10.1016/j.yrtph.2023.105505. Online ahead of print.ABSTRACTN-nitrosamines (NAs) are a class of compounds of which many, especially of the small dialkyl type, are indirect acting DNA alkylating mutagens. Their presence in pharmaceuticals is subject to very strict acceptable daily intake (AI) limits, which are traditionally expressed on a mass basis. Here we demonstrate that AIs that are not experimentally derived for a specific compound, but via statistical extrapolation or read across to a suitable analog, should be expressed on a molar scale or corrected for the target subs...
Source: Regulatory Toxicology and Pharmacology : RTP - October 7, 2023 Category: Toxicology Authors: Jonathan Fine Leonardo Allain Joerg Schlingemann David J Ponting Robert Thomas George E Johnson Source Type: research