Chemical hazards, definition

Chemical Hazards Definitions and Assessment, 113 Emergency Planning and Incident Management, 123 Hazard Communication, 130 Workplace Safety, 134... 

The hazard communication standard is published in Title 29 of the Code of Federal Regulations, paragraph 1910.1200. OSHA regulations affecting research laboratories are published in 29 CFR 1910 seq. Chapter 12 contains specific details about the nature of chemical hazards, definitions of health and physical hazards, and discussions of precautions necessary in handling chemicals. 

Typical units for LDjq values are milligrams or grams of material per kilogram of body weight (mg/kg or g/kg, recall that 1 kg = 2.2 pounds). Never be exposed to an LD50 dose of a hazardous chemical- by definition, there is a 50% chance this will kill you and if you survive you are not going to be in good shape. Pay close attention to the permissible exposure level (PEL) instead. This is a more realistic determination of the maximum safe exposure to a material and is usually based on the known effects of the chemical on humans, rather than laboratory animals. 

In tracing the life of a new chemical, a definition of the intensity and nature of hazard is necessary at the general stages of development shown in Table II. 

Pilot Plant—Chemical reaction hazards Influence of plant selection on hazards Definition of safe procedures Effects of expected variations in process conditions Definition of critical limits... 

This chapter covered only a small proportion of the vast number of chemicals that can be found in the workplace. For more definitive information on a wide variety of toxic substances, the reader is referred to standard references on industrial toxicology. Of these, one of the most useful for a quick summary of toxic effects and management is Chemical Hazards in the Workplace by N. H. Proctor and J. P. Hughes. Definitive reviews of many chemicals are published by the American Industrial Hygiene Association and the National Safety Council among others. Sources are given in Appendix III. 

Throughout this book, the OECD/IPCS terms and definitions in chemical hazard and risk assessment will be used unless otherwise stated. The OECD/IPCS terms are generally concordant with those used by the US-EPA and the EU. 

Other terms often used indiscriminately for the dose-response relationship include concentration-effect relationship and dose-effect relationship. According to the joint OECD/IPCS project (OECD 2003 a), which has developed internationally harmonized generic and technical terms used in chemical hazard and risk assessment, the following definitions have been provided although consensus was not achieved ... 

Chemical Hazards. Chemical hazards are many and varied. It should be taken for granted that any chemical substance taken by mouth or inhaled is toxic until and unless definite assurance has been given to the contrary. Reactions that produce toxic fumes or vapors or entail risk of fire should always take place in a fume hood. As a matter of standard safety practice, never pipette any liquid or solution by mouth use a rubber pipetting bulb. Another insidious hazard is that of vapors from organic solvents. Such solvents should not be used indiscriminately for cleaning purposes, and spills should be avoided. Good ventilation is important. 

The use of animals for routine toxicity testing is now questioned by a growing segment of society. If currently used animal tests are to be successfully replaced, it is important to demonstrate that the alternative methods provide chemical hazard data equivalent to that now available from animal-based tests. Additionally, in order for toxicologists to take the best advantage of new technologies that are constantly evolving, it is important that the validation process be conducted in a manner that efficiently and definitely characterizes the performance of new test methods. 

The Institution also developed definitions for a chemical hazard and a major hazard. It called a chemical hazard a hazard involving chemicals or processes which may realize its potential through fire, explosion, toxic or corrosive effects and, a major hazard as an imprecise term for a larger scale chemical hazard, especially one which may be realized through an acute event . 

Hazardous Chemical any chemical (see definition) that presents a physical hazard or a health hazard. A substance that possesses potentially hazardous properties (including, but not limited to flammability, toxicity, corrosivity, reactivity). 

This chapter identifies and consolidates existing user safety and health requirements found in DOE and Federal chemical-related safety and health regulations and National Standards that address hazard analysis of activities involving chemicals (see definition) and chemical products (see definition). 

Safety hazards related to the physical characteristics of a chemical can be defined in terms of testing requirements, such as ignitability however, health hazard definitions are less precise and more subjective. There have been many attempts to categorize effects and to define them in various ways. Generally, the terms acute and chronic are used to delineate between effects on the basis of severity or duration. Acute effects occur rapidly as a result of short-term exposures. Chronic effects occur as a result of long-term exposures. 

OSHA issued its HAZCOM standard to address the assessment and communication of chemical hazards in the workplace. This standard has often been referred to as the worker s right to know standard. This standard is intended to help protect employee safety and health in work sites where chemicals are used or present. There is no list of hazardous chemicals. Instead, OSHA has defined two categories of hazardous materials health hazards and physical hazards. If a material meets one of OSHA s definitions, it is considered a hazardous chemical. Every company which uses hazardous chemicals, must have a written hazard communication program. This program must be available to employees, and be provided to OSHA upon request. The most important element of the entire right-to-know program is employee training and education. 

Material Safety Data Sheets, which are now required to be provided by distributors and manufacturers of commercial chemicals, give detailed information on the characteristics of all commonly sold laboratory chemicals. The definitions of explosive, flammable, combustible, and various healthhazards are consistent with those provided by OSHA in CFR 29, Parts Table 3.2 Exemption Limits for a Few Critical Classes of Materials Representing Health Hazards For a Class 4, Hazardous Use Occupancy... 

CAS No. is the Chemical Abstracts Service Registry Number PEL is from 29 CFR 1910.1000, Table Z-1 American Conference on Governmental Industrial Hygienists (ACGIH), threshold limit value (TLV) under the HCS, a MSDS is required for aU of the compounds (physical and/or chemical hazard) all of the solvents are flammable liquids or gasses, under the OSHA definition, and are regulated under the PSM Standard. 

The current definition has no exposure duration associated with it. Workers should not be in an IDLH environment for any length of time unless they are equipped and protected to be in that environment. IDLH values were determined based on animal and human data. They may be found in the NIOSH Pocket Guide to Chemical Hazards. ... 

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