4.1 Application of this guide will provide information on the acute toxicity of water-miscible metalworking fluids and will assist the user in evaluating the potential health hazards of the fluid and developing appropriate work practices. A water-miscible metalworking fluid is a concentrate designed to be diluted in water for use.

4.2 Water-miscible metalworking fluids are complex chemical mixtures. The United States Occupational Safety and Health Administration (OSHA) Hazard Communication Standard (see A1.8) outlines procedures for the hazard determination of mixtures and states that if a mixture has not been tested as a whole, then the mixture shall be assumed to present the same hazards as do the components that comprise 1 % (by weight or volume) or greater of the mixture, except that the mixture shall be assumed to present a carcinogenic hazard if it contains a component in concentrations of 0.1 % or greater, which is considered to be a carcinogen (as defined in OSHA Standard 29 CFR 1910.1200). The determination of when to test a mixture as a whole and which toxicity tests are appropriate for the product must be made by a health professional, qualified in evaluating toxicological data.

4.3 Acute toxicology testing of water-miscible metalworking fluids consists of several individual tests including acute oral, dermal, or inhalation toxicity, eye irritation, skin irritation or corrosion, or both, skin sensitization, and sensory irritation. Certain protocols for acute oral, dermal, and inhalation toxicity tests are limit tests; further multi-dose testing (for example, Test Method E1103) should take place if mortality is noted on any of these tests. The referenced protocols specify the species and number of animals required. Selection of tests conducted should be designed to minimize the number of animals used.

4.3.1 Acute Oral Toxicity—Acute oral toxicity tests (see A1.1) provide information on health hazards likely to arise from short-term exposure by the oral route. Results of this type of test are used to develop warning statements on labels as may be required by OSHA Hazard Communication Standard 29 CFR 1910.1200 (see A1.8) or Federal Hazardous Substances Act (see A1.10). These are also used to establish a dosage regimen for subchronic and other testing. Endpoint: mortality.

4.3.2 Acute Dermal Toxicity—Acute dermal toxicity tests (see A1.2) provide information on health hazards likely to arise from short-term exposure by the dermal route and may provide initial information on dermal absorption and the mode of toxic action of a substance. In addition, some measure of irritation caused by the fluid may be obtained by observing local tissue damage at the sight of application. Endpoint: mortality.

4.3.3 Acute Inhalation Toxicity—Acute inhalation toxicity tests give an indication of relative toxicity (see A1.3). The results provide an indication of the potential of the fluid to cause death and other adverse health effects when inhaled for a specified time period. Endpoint: mortality.

4.3.4 Eye Irritation—Eye irritation tests provide an indication of the potential of the fluid to cause eye irritation or damage upon direct contact (see A1.4). An irritant is defined as a chemical that is not corrosive, but causes a reversible inflammatory effect on living tissue by chemical action at the site of contact. Endpoint: degree of irritation.

4.3.5 Skin Irritation or Corrosion—Skin irritation or corrosion tests indicate the potential of the fluid to produce irritation or damage to skin (see A1.5). A corrosive chemical is one that causes visible destruction of, or irreversible alterations in, living tissue by chemical action at the site of contact. Endpoint: irritation or corrosion.

4.3.6 Skin Sensitization—A chemical sensitizer is a material that causes a substantial proportion of exposed people or animals to develop an allergic reaction in normal tissue after repeated exposure to the chemical. A number of methods are available for measuring skin sensitization, however, there are differences in opinion on the most appropriate method. These are due to variations in compound administration and degree of reaction to a sensitizing substance. Refer to the Code of Federal Regulations (CFR) for the various protocols (see A1.6). Additionally, toxicology testing contract labs may have standard procedures for conducting these assays. Endpoint: sensitization.

4.3.7 Sensory Irritation-—Upon exposure to a sensory irritant, humans experience discomfort or a burning sensation of the eyes, nose, and throat, and may also cough. Test Method E981 (see A1.2.5) provides a means to evaluate the sensory irritant potential of airborne chemicals and mixtures as well as a means to assess the comparative irritancy of compounds and formulations. However, this test method cannot be used to evaluate the relative obnoxiousness of odors. End point: upper respiratory tract irritation.

4.4 A number of federal guidelines can be used to establish general procedures for testing acute toxicity of metalworking fluids. Several references are cited in Annex A1. Regardless of the method used, Good Laboratory Practices, as outlined by the United States Environmental Protection Agency (EPA 40 CFR 792) (see A1.9) must be followed. The OSHA Hazard Communication Standard (see A1.8) outlines the responsibilities of chemical manufacturers, importers, and employers in the determination of chemical hazards and communication of information on those hazards.

4.5 The methods referenced in this guide or appropriate alternate methods such as those suggested by the Organization for Economic Cooperation and Development (OECD) are acceptable for testing the acute toxicity of water-miscible metalworking fluids. For each test outlined in Annex A1.1-A1.5, a table is included that highlights the similarities and differences between the test protocols.

1.1 This guide defines acute animal toxicity tests and sets forth the references for procedures to assess the acute toxicity of water-miscible metalworking fluids as manufactured.

1.2 Although water-miscible metalworking fluids are typically used at high dilution, dilution rates vary widely. Additionally, there is potential for exposure to the metalworking fluid as manufactured.

1.3  This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.