Irritation and corrosiveness

Is SM an irritant or a corrosive The Chemicals (Hazard Information and Packaging for Supply) Regulations (2009) define corrosives as substances and preparations which may on contact with living tissues, destroy them and irritant chemicals as non-corrosive substances which, through immediate, prolonged or repeated contact with the skin or mucous membrane, may cause inflammation . SM does not destroy tissues on immediate contact, but produces an inflammatory response that results in tissue destruction. As such, SM is an irritant, although it can produce injuries of such severity that they are similar to those produced by a corrosive. 

Similar histopathological changes have been observed in miee and Yucatan mini-pigs. Pig skin is histologically and biochemically similar to that of humans and the pathology of SM injury is also similar in time 

A more detailed study showed similar effects in guinea pigs and rabbits treated with doses between 25 and 250 pg cm applied to the skin in methylene chloride. These authors described the time course of lesion development and healing, which was similar in both species over the entire dose range (Table 2.3). 

Studies of the effects of 10 pi of SM, vaporised (8 min), or 2 pi of SM liquid (30 min) applied to the skin of hairless guinea pigs revealed similar injuries to those seen in the rabbit and furred guinea pig. At 12-24 hours the basal and supra-basal epidermal cells showed extensive cytoplasmic vacuoli-sation, swollen endoplasmic reticulum, nuclear pyknosis and cellular necrosis. Microblisters were evident. 

12-18 hours Erythema and oedema extended well beyond the application site 24-48 hours Centre of the lesion appeared blanched with some petechial bleeding 

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There is no specific antidote for acrolein exposure. Treatment of exposure should be directed at the control of symptoms and the clinical condition. Most of the harmful effects of acrolein result from its highly irritating and corrosive properties. 

Handling and Toxicity. Tungsten hexafluoride is irritating and corrosive to the upper and lower airways, eyes, and skin. It is extremely corrosive to the skin, producing bums typical of hydrofluoric acid. The OSHA permissible exposure limits is set as a time-weighted average of 2.5 mg/kg or 0.2 ppm (22). 

Hydrogen fluoride Catalyst in some petroleum refining, etching glass, silicate extraction by-product in electrolytic production of aluminum Petroleum, primary metals, aluminum Strong irritant and corrosive action on all body tissue damage to citrus plants, effect on teeth and bones of cattle from eating plants... 

Typical precautions for work with irritant and corrosive chemicals are listed in Table 5.45. 

Toxic Reactions of the Skin Irritation is the most common reaction of the skin. Skin irritation is usually a local inflammatory reaction. The most common skin irritants are solvents dehydrating, oxidizing, or reducing compounds and cosmetic compounds. Acids and alkalies are common irritants. Irritation reactions can be divided into acute irritation and corrosion. Necrosis of the surface of the skin is typical for corrosion. Acids and alkalies also cause chemical burns. Phenols, organotin compounds, hydrogen fluoride, and yellow phosphorus may cause serious burns. Phenol also causes local anesthesia, in fact it has been used as a local anesthetic in minor ear operations such as puncture of the tympanous membrane in cases of otitis. ... 

Acetic anhydride (acetyl oxide) is a liquid with a strong offensive odor. It is an irritating and corrosive chemical that must be handled with care. 

Much toxicological data are available on this red pigment acute oral toxicity in mice, 90-day subchronic toxicological study, acute dermal irritation and corrosion, acute eye irritation and corrosion, anti-tumor effectiveness, micronucleus test in mice, AMES test Salmonella typhimurium reverse mutation assay), estimation of antibiotic activity, and results of estimation of five mycotoxins. A new patent on Arpink Red was filed in 2001 with claims of anti-cancer effects of the anthraquinone derivatives and apphcations in the food and pharmaceutical fields. 

Lethal concentrations and doses are parameters of acute, systemic poisoning. There are also specific protocols to evaluate the irritant and corrosive effects on skin, eyes and mucous membranes. 

The platform includes different decision trees for the following endpoints the estimation of Threshold of Toxicological Concern (TTC), aquatic modes of action [44], skin and eye irritation and corrosion, mutagenicity and carcinogenicity [45], in vivo micronucleus assay, identification of Michael Acceptors and biodegradation potential [46]. 

This approach may find application in peptide bond formation that would eliminate the use of irritating and corrosive chemicals such as trifluoroacetic acid and piperidine as has been demonstrated recently for the deprotection of N-boc groups (Scheme 6.7) a solvent-free deprotection of N-tert-butoxycarbonyl group occurs upon exposure to microwave irradiation in the presence of neutral alumina doped with aluminum chloride (Scheme 6.7) [41]. 

Draize Scoring System for Evaluation of Skin Irritating and Corrosive Properties... 

The TGD (EC 2003), Chapter 3.7, addresses irritation and corrosion and provides guidance on data requirements, evaluation of data, and dose-response assessment. 

Differences among species in distribution patterns of histological changes may be caused by species variations in the distribution in the nasal epithelium of chemical-metabolizing enzymes. For example, in rats exposed to methyl methacrylate, nasal lesions were shown to be caused by the carboxylesterase mediated metabolism of methyl methacrylate to methacrylic acid, an irritant and corrosive metabohte. The distribution of these enzymes in the nasal tissues of man, rat, and hamster indicated a lower rate of metabolism in man compared to rat and hamster, suggesting a lower sensitivity to methacrylate in humans (Mainwaring et al. 2001). 

The risk characterization is carried out by quantitatively comparing the outcome of the hazard (effects assessment) to the outcome of the exposure assessment, i.e., a comparison of the NOAEL, or LOAEL, and the exposure estimate. The ratio resulting from this comparison is called the Margin of Safety (MOS) (MOS = N(L)OAEL/Exposure). This is done separately for each potentially exposed population, i.e., workers, consumers, and man exposed via the environment, and for each toxicological endpoint, i.e., acute toxicity, irritation and corrosion, sensitization, repeated dose toxicity, mutagenicity, carcinogenicity, and toxicity to reproduction. 

The toxicity of lithium hydride differs markedly from that of the soluble salts of lithium because of its vigorous chemical reactivity with water, which produces acute irritation and corrosion of biological tissues. ... 

Toxicology. Sulfur tetrafluoride is extremely irritating and corrosive to the respiratory tract, skin, and eyes. 

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