Irritant/corrosive chemicals

In conclusion, it is important to be able to estimate the real effect and behavior of irritant/cor-rosive products for cosmetic use such as chemical peeling or hair relaxers. Controlling the pH after exposure to these aggressive products can stop the burning process and improves the awaited effect irritant/corrosive chemical agent for cosmetic use seems to be important. See also Sect. 4.11.3 on peeling. 

For in vitro experimental data with TCA, see section Use of irritant/corrosive chemical products as cosmetics . 

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

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. 

A summary of the more common corrosive chemicals is given in Table 4.4. Note that this includes many primary irritants, such as ... 

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]. 

Safety equipment such as helmets, steel capped boots, and hearing protectors are, of course, important and should be used when the situation warrants. Our discussion here, however, is concerned with the protection of the eyes and skin in the presence of chemicals that are irritant, corrosive, or capable of penetration. 

OECD has published a document on a Harmonised Integrated Classification System for Human Health and Environmental Hazards of Chemical Substances and Mixtures (OECD 2001b). Chapters 2.2 and 2.3 address a harmonized system for the classification of chemicals, which cause skin and eye irritation/corrosion, respectively. 

The ocular chemical bum is the result of the destruction of a more or less important quantity of biochemical constituents of the cells of living tissues when in contact with an irritant or corrosive chemical. 

Polyvalence because of the diversity of substances and often because of the misknowledge of the precise composition of the irritant or corrosive chemicals involved. 

For the irritating or corrosive chemicals we are concerned with here, the top priority is to break the prodnct-human tissue contact. This can be done in two ways ... 

OECD Guideline for Testing Chemicals, Section 4, number 404 Acute Dermal Irritation/Corrosion , adopted April 24, 2002. 

In the evaluation of a chemical s toxic characteristics, determination of the irritant/corrosive effects on the eyes of mammals is an important parameter. Data obtained from this test indicate hazards likely to arise from exposure of the eyes and associated mucous membranes to the toxic chemical under test. 

OECD (1993) Acute dermal irritation/corrosion. In OECD Guidelines for Testing of Chemicals. Section 4, 35 404. Organization for Economic Cooperation and Development, Paris, France... 

Exposure to a chemical can cause damage at the point or site of exposure if the substance is reactive, irritant, corrosive, or caustic. Thus substances such as kettle descaler (formic acid), battery acid (sulphuric acid), caustic soda (sodium hydroxide), and bleach (sodium hypochlorite/hypochlorous acid) can cause serious, and maybe permanent, damage to the skin, the eyes or the oesophagus, and stomach if they come into contact with these parts of the body. Unfortunately, people sometimes attempt suicide by swallowing such substances for example, drinking kettle descaler or bleach causes serious damage to the lining of the gut (see case notes, p- 193). 

DOT CLASSIFICATION 8 Label Corrosive SAFETY PROFILE Poison by inhalation. Moderately toxic by ingestion. A severe eye, skin, and mucous membrane irritant. Corrosive to body tissues. Flammable by chemical reaction. Explosive reaction with chlorine dioxide + chlorine, sodium, urea + heat. Reacts to form explosive products with carbamates, 3 -methyl-2-nitroben2anilide (product explodes on contact with air). Ignites on contact with fluorine. Reacts violently with moisture, CIO3, hydroxyl-amine, magnesium oxide, nitrobenzene, phosphorus(III) oxide, K. To fight fire, use CO2, dry chemical. Incompatible with aluminum, chlorine dioxide, chlorine. 

Wear gloves for toxic, irritant or corrosive chemicals and carry out procedures with them in the fume cupboard. 

Gerner I and Schlede E (2002) Introduction of in vitro data into local irritation/corrosion testing strategies by means of SAR considerations Assessment of chemicals. Toxicology Letters 127 169-175. 

Corrosive. A corrosive chemical is one that causes visible destruction of, or irreversible alterations in, respiratory tract tissue upon inhalation of vapors, mists, or fine particulates by chemical action at the site of contact. For most chemicals, corrosivity is a function of concentration. At sufficiently low concentrations, corrosive chemical vapors may act as irritants. Hydrogen chloride, nitrogen dioxide, and sodium hydroxides are examples of chemicals corrosive to the respiratory system. 

The exact mechanism by which formaldehyde exerts its irritant, corrosive, and cytotoxic effects is not known. Aldehydes as a group are reactive chemicals with a highly electronegative oxygen atom and less electronegative atoms of carbon(s), and hence have a substantial dipole moment. The carbonyl atom is the electrophilic site of these type of molecules, making it react easily with nucleophilic sites on cell membranes and in body tissues and fluids such as the amino groups in protein and DNA (Feron et al. 

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