Skin Irritation or Corrosion

Corrosion to the skin is measured by patch-test technique on the intact skin of the albino rabbit, clipped free of hair. A minimum of six subjects are to be used in this test. 

Introduce under a square cloth patch, such as surgical gauze measuring not less than 1 inch by 1 inch and two single layers thick, 0.5 milliliter (in the case of liquids) or 0.5 gram (in the case of solids and semisolids) of the substance to be tested. 

Immobilize the animals with patches secured in place by adhesive tape. 

Wrap the entire trunk of each animal with an impervious material, such as rubberized cloth, for the 4 hour period of exposure. This material is to aid in maintaining the test patches in position and retard the evaporation of volatile substances. It is not applied for the purpose of occlusion. 

After 4 hours of exposure, the patches are to be removed and the resulting reactions are to be evaluated for corrosion. 

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The acute oral toxicity and the primary skin and acute eye irritative potentials of dimer acids, distilled dimer acids, trimer acids, and monomer acids have been evaluated based on the techniques specified ia the Code of Eederal Regulatioas (CER) (81). The results of this evaluatioa are showa ia Table 7. Based oa these results, monomer acids, distilled dimer acids, dimer acids, and trimer acids are classified as nontoxic by ingestion, are not primary skin irritants or corrosive materials, and are not eye irritants as these terms are defined ia the Eederal regulatioas. 

Skin irritation or corrosivity evaluation or in vitro tests... 

Among the most fundamental assessments of the safety of a product or, indeed, of any material that has the potential to be in contact with a significant number of people in our society are tests which seek to predict potential skin irritation or corrosion. Like all the other tests in what is classically called a range-finding. 

The acid-base couple is the most known because of the massive and ubiquitous use of the acids and bases at work and in the everyday life or during chemical assaults. But it is not the only cause of skin irritation or corrosion. An oxidizer or a reducing agent can also generate lesions to tissues. 

Professional operators use biocidal agents as disinfectants for veterinary hygiene (e.g., slaughterhouses), drinking water, private and public health areas, and as insect repellents. The European Union has labeled many of these as skin irritants or corrosives [141]. 

The skin is often exposed, either intentionally or nnintentionally, to cosmetic prodncts. It is clear that the potential for a particnlar prodncEingredient to cause skin irritation or corrosion needs to be carefully evaluated as part of the overall safety assessment process. 

Health Hazards Information - Recommended Personal Protective Equipment Suitable respirator (For dust) rubber gloves chemical goggles or face shield Symptoms Following Exposure Inhalation of dust causes irritation of nose and throat. Ingestion can cause irritation or corrosion of the alimentary tract, circulatory collapse, and toxic nephritis. Contact with eyes or skin causes irritation General Treatment for Exposure INHALATION move to flesh air if exposure has been severe, gel medical attention. 

As far as man and animals are concerned, the economic poisons exert their harmful and deleterious effect after absorption and distribution through the blood stream. Relatively few agents are irritating or corrosive in their action, and their effect on the intact skin may be considered secondary (5, 8). Toxic action of economic poisons is exerted by alteration in physiologic or biochemical activity of various systems, organs, and cells. 

Specialized equipment can minimize exposure to the hazards of laboratory operations. Impact resistant safety glasses are basic equipment and should be worn at all times. They may be supplemented by face shields or goggles for particular operations, such as pouring corrosive liquids. Because skin contact with chemicals can lead to skin irritation or sensitization or, through absorption, to effects on internal organs, protective gloves are often needed. 

A general definition of the term acute toxicity is The adverse effects occurring within a given time, following a single exposure to a substance. The term usually excludes local irritant or corrosive effects arising from a single application of a substance to the skin or eye (Section 4.5) (EC 2003). 

Substances, which are skin or eye irritating or corrosive after single exposure (Section 4.5) should be suspected of inducing local effects upon repeated respiratory exposure to low concentrations. In contrast, local effects reported from skin sensitization studies as well as dermal repeated dose toxicity studies are not predictive of local effects on the respiratory tract. In addition, observations from irritation and/or sensitization studies as well as repeated dose inhalation toxicity studies are not predictive of local effects on the skin upon repeated dermal exposure (EC 2003). 

Topical drug preparations are applied for days or even weeks, cosmetics for a lifetime and skin contact is probably the most common form of exposure to industrial chemicals. Therefore, a knowledge of the cutaneous toxicity is important for an overall hazard assessment. Cutaneous toxicity or localised skin injury can be considered as a primary event, because the compound could be irritant or corrosive, or as a secondary immunologically mediated event causing a delayed hypersensitivity response. 

In direct contact with the skin or mucous membranes propylene oxide has an irritant or corrosive effect, depending on the concentration allergic contact dermatitis has been reported, and corneal burns from the vapor have also been described. ... 

The potential of Ecoflex (powder) to cause acute dermal irritation or corrosion was assessed by a single topical application of the test substance to the intact skin of rabbits according to OECD guideline 404. After removal of the patch, the application area was washed off and cutaneous reactions were assessed for 72 h. No cutaneous reactions were observed. Hence, Ecoflex (powder) is not irritating to skin. 

The acute dermal irritation is the study of reversible inflammatory changes in the skin of test animals following the application of a test chemical. Acute dermal corrosion is the study of irreversible tissue damages in the skin following the application of a test chemical. In the evaluation of toxic characteristics of a chemical, determination of the irritant or corrosive effects on mammal skin is an important study step. Information derived from this test indicates the existence of hazards likely to arise from skin exposure to the test chemical. 

Many chemicals however, will have no direct adverse effect on the tissues of the skin, lungs, or gut when these are exposed. In order to have any effect they must be absorbed into the body. There are some chemicals that are not absorbed and are not irritant or corrosive, which consequently wiU have no effect on the body. 

DOT CLASSIFICATION 8 Label Corrosive SAFETY PROFILE Moderately toxic by ingestion and skin contact. An eye and severe skin irritant. A corrosive material. It fumes in moist air, releasing HCl. Combustible when exposed to heat or flame. When heated to decomposition it... 

In general, the approach to classification of mixtures as irritant or corrosive to skin when data are available on the components, but not on the mixture as a whole, is based on the theory of additivity, such that each corrosive or irritant component contributes to the overall irritant or corrosive properties of the mixture in proportion to its potency and concentration. A weighting factor of 10 is used for corrosive components when they are present at a concentration below the concentration limit for classification with Category 1, but are at a concentration that will contribute to the classification of the mixture as an irritant. The mixture is classified as corrosive or irritant when the sum of the concentrations of such components exceeds a cut-off value/concentration limit. 

General and specific considerations concerning labelling requirements are provided in Hazard communication Labelling (Chapter 1.4). Annex 2 contains summary tables about classification and labelling. Annex 3 contains examples of precautionary statements and pictograms which can be used where allowed by the competent authority. The table below presents specific label elements for substances and mixtures that are classified as irritating or corrosive to the skin based on the criteria set forth in this chapter. 

Most of the chemicals listed produce vapors that target the respiratory system and the CNS. All are dangerous if ingested and all are irritating or corrosive to dermal and eye tissues. Mixtures of either alkalis or acids with lipophilic solvents (e.g., toluene, aliphatic hydrocarbons) produce enhanced burn effects. Skin and eyes exposed to chemicals that can burn... 

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