Contrasting directions and directives on hazard identification for formaldehyde carcinogenicity

Clove essential oil in the sanitation of fertile eggs

The aim of this study was to evaluate the efficacy of sanitizing fertile eggs with clove essential oil as an alternative to paraformaldehyde; effects on the reduction in eggshell microbial count, incubation yield, and neonatal chick quality were measured. A total of 1,460 brown fertile eggs with a mean weight of 58.64 ± 0.49 g (from 37-wk-old CPK [Pesadão Vermelho] breeder hens) were collected under aseptic conditions and randomly distributed into 4 treatments (nonsanitized and sanitized with grain alcohol, clove essential oil, and paraformaldehyde) before incubation. The count of total aerobic mesophilic bacteria was significantly lower after spraying with clove essential oil (2.30 ± 0.24 log₁₀ CFU/mL) than on nonsanitized eggs (3.49 ± 0.34 log₁₀ CFU/mL) or on eggs sprayed with grain alcohol (3.09 ± 0.14 log₁₀ CFU/mL) but did not differ significantly from the count in the paraformaldehyde group (2.23 ± 0.29 log₁₀ CFU/mL). The hatchability of fertile eggs differed significantly between the studied treatments. The mean values for the eggs treated with clove essential oil (84.69 ± 1.65%) and paraformaldehyde (81.87 ± 3.92%) were statistically similar but were higher than the negative control (74.03 ± 3.58%) and grain alcohol (73.59 ± 2.87%) values. In the Pasgar© score assessment, it was determined that the clove essential oil (9.21 ± 0.89%) had a superior effect on the physical quality of the chicks compared with the effects of the other treatments. Clove essential oil is effective and safe for eggs intended for incubation. Its use as an alternative to paraformaldehyde in the sanitation of fertile eggs is strongly recommended.

Six years after the NRC review of EPA's Draft IRIS Toxicological Review of Formaldehyde: Regulatory implications of new science in evaluating formaldehyde leukemogenicity

Shortly after the International Agency for Research on Cancer (IARC) determined that formaldehyde causes leukemia, the United States Environmental Protection Agency (EPA) released its Draft IRIS Toxicological Review of Formaldehyde ("Draft IRIS Assessment"), also concluding that formaldehyde causes leukemia. Peer review of the Draft IRIS Assessment by a National Academy of Science committee noted that "causal determinations are not supported by the narrative provided in the draft" (NRC 2011). They offered recommendations for improving the Draft IRIS assessment and identified several important research gaps. Over the six years since the NRC peer review, significant new science has been published. We identify and summarize key recommendations made by NRC and map them to this new science, including extended analysis of epidemiological studies, updates of earlier occupational cohort studies, toxicological experiments using a sensitive mouse strain, mechanistic studies examining the role of exogenous versus endogenous formaldehyde in bone marrow, and several critical reviews. With few exceptions, new findings are consistently negative, and integration of all available evidence challenges the earlier conclusions that formaldehyde causes leukemia. Given formaldehyde's commercial importance, environmental ubiquity and endogenous production, accurate hazard classification and risk evaluation of whether exposure to formaldehyde from occupational, residential and consumer products causes leukemia are critical.

Glyphosate toxicity and carcinogenicity: a review of the scientific basis of the European Union assessment and its differences with IARC

Glyphosate is the most widely used herbicide worldwide. It is a broad spectrum herbicide and its agricultural uses increased considerably after the development of glyphosate-resistant genetically modified (GM) varieties. Since glyphosate was introduced in 1974, all regulatory assessments have established that glyphosate has low hazard potential to mammals, however, the International Agency for Research on Cancer (IARC) concluded in March 2015 that it is probably carcinogenic. The IARC conclusion was not confirmed by the EU assessment or the recent joint WHO/FAO evaluation, both using additional evidence. Glyphosate is not the first topic of disagreement between IARC and regulatory evaluations, but has received greater attention. This review presents the scientific basis of the glyphosate health assessment conducted within the European Union (EU) renewal process, and explains the differences in the carcinogenicity assessment with IARC. Use of different data sets, particularly on long-term toxicity/carcinogenicity in rodents, could partially explain the divergent views; but methodological differences in the evaluation of the available evidence have been identified. The EU assessment did not identify a carcinogenicity hazard, revised the toxicological profile proposing new toxicological reference values, and conducted a risk assessment for some representatives uses. Two complementary exposure assessments, human-biomonitoring and food-residues-monitoring, suggests that actual exposure levels are below these reference values and do not represent a public concern.

Assessment of the effect of selected substances used for disinfection of hatching eggs on hatching results in chickens

The aim of the study was to investigate whether egg disinfectants have a toxic effect on the tissues of the developing chicken embryo. The basic active ingredients of the disinfectants tested were quaternary ammonium compounds (Amino-Steril); stabilized peracetic acid and hydrogen peroxide (Oxydion); glutaraldehyde, didecyldimethylammonium chloride, quaternary ammonium compounds and benzyl-C12-C16-alkyldimethyl (Viron FF); and stabilized hydrogen peroxide (Hydro-Clean). The tests were performed on hatching eggs from Ross 308 parent stock. The potential adverse effects of aqueous solutions of the disinfectants were tested in vitro using the Hen’s Egg Test – Chorioallantoic Membrane (HET-CAM). The results were confirmed in in vivo tests by analysing the hatchability of disinfected eggs. In the in vitro tests, aqueous solutions of the disinfectants with concentrations of 1%, 0.5%, 0.25% and 0.125% were spotted onto previously prepared chorioallantoic membranes of live eight-day-old chicken embryos (n = 8 embryos/disinfectant/concentration). The toxicity of the substances was assessed on the basis of the occurrence of hyperaemia, haemorrhage, and coagulation of the blood vessels of the membrane after 0.5, 2 and 5 minutes, using the 21-point Luepke scale. The in vivo testing consisted of two experiments conducted under production conditions, using eggs from flocks in the peak (37th week of life) and the final (54th week) laying periods. The eggs were sprayed with a 1% aqueous solution of disinfectant (400 eggs/disinfectant/experiment) about 2 hours before incubation. Hatching results, the stage of embryonic development at the time of death and any cases of infection were evaluated. The HET-CAM tests showed that the 1% solutions of the disinfectants induced strong (Hydro-Clean), moderate (Oxydion and Amino-Steril) and weak (Viron FF) reactions, while the 0.125% concentration produced a weak reaction or none. Analysis of hatching results showed that they were not affected by the disinfectants. However, in the case of laying hens in their final production period, spraying with aqueous solutions of each agent reduced losses due to early embryo mortality. In conclusion, the disinfectants tested can be safely used in poultry hatcheries