Regulatory Test Methods

The Steiner Tunnel test (ASTM E 84) is used to classify the fire-spread potential of products used in wall and ceiling linings [4], and is used to classify expanded polystyrene foam. In this method, specimens are placed on the ceiling of a 24 ft long tunnel. An 88 kW natural gas burner is placed at one end of the tunnel and a forced-air draft with a velocity of 1.22 m/s is introduced. The flame spread is recorded as a function of time and an arbitrary index is calculated from the measurements. 

This test has been criticized because it does not simulate actual building fire conditions [5,6], An additional problem with foamed samples is that the specimens either retract out of the reach of the flame or drip on to the floor of the tunnel. In Canada this has been addressed by using a downward-facing burner and mounting the specimens on the floor of the tunnel. Despite its limitations, the Steiner Tunnel method continues to be used to test and rate thermoplastic foams. 

There are a number of different 94 V classifications, the best being 94 V-0. To pass this requirement, none of the individual burn times can be greater than 10 s and the total of the 10 burn times must be less than 50 s. There are a number of other requirements for this rating none of the specimens may bum up to the clamp, none may drip flaming particles that ignite cotton-wool placed under the specimen and for the second flames the total of the bum time and afterglow cannot exceed 30 s. 

For a UL 94 V-l rating the individual bum times are less than 30 s and the total of all bum times is less than 250 s in addition, there should not be any flaming drips. For a UL 94 V-2 rating the same restrictions apply for bum times, but flaming drips are allowed. 

For samples that cannot meet the requirements for the UL 94 V test, the UL 94 HB horizontal burn test is a possibility. Flame spread in the horizontal orientation is much slower than for the vertical test. Two marks are made on the bar at 25.4 and 101.6 mm from the free end of the specimen. After the flame has been applied for 30 s, the burn rate between the reference marks 

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SM is widely known for its vesicating properties. There are no documented studies that conform to any standard regulatory test method for dermal irritation/corrosivity. However, there is sufficient information from observations and tests in humans to establish SM as a primary irritant, and further tests in animals are not required. 

TABLE 25-31 Regulatory Citations for Selected Test Methods... 

A waste is toxic under 40 CFR Part 261 if the extract from a sample of the waste exceeds specified limits for any one of eight elements and five pesticides (arsenic, barium, cadmium, chromium, lead, mercury, selenium, silver, endrin, methoxychlor, toxaphene, 2,4-D and 2,4,5-TP Silvex using extraction procedure (EP) toxicity test methods. Note that this narrow definition of toxicity relates to whether a waste is defined as hazardous for regulatory purposes in the context of this chapter, toxicity has a broader meaning because most deep-well-injected wastes have properties that can be toxic to living organisms. 

The term alternative includes all procedures which can completely replace the need for animal experiments, reduce the number of animals required, or diminish the amount of distress or pain suffered by animals in meeting the essential needs of man and other animals. Its purpose is to promote the development and implementation of new methods to Replace, Reduce, Refine (the 3 Rs ) animal testing with modem alternative approaches. Russell and Burch [4] proposed the framework of the 3 Rs more than 40 year ago. The authors proposed that all research using animals should be evaluated to see if the 3 Rs could be applied. Since that landmark publication, significant progress has been made, especially in the arena of regulatory testing [5]. 

However, the differences between the national test methods are considered to be the major barrier to trade. Whilst the harmonization of test and classification systems is insufficient on its own to provide for a free market, it is undoubtedly a necessary condition to it. Without a common method of evaluating the fire behaviour, there is no basis for a common regulatory specification. 

There are no regulatory guidelines or suggested test methods for evaluating agents for muscular or vascular irritation. Since such guidelines are lacking, but the evaluation is necessary, those responsible for these evaluations have tried to develop and employ the most scientifically valid procedures. 

Some modifications to current in vivo testing methods both can and should be adopted. A current example of this would be in medical devices where a substantial portion of the requirements under the governing regulatory (ISO 10993) can be met with in vitro alternatives (cytogenicity, muscle cell implantation, the limulus test for pyrogens, and in vitro mutagenicity assays). 

To determine the concentrations of benzene, toluene, ethylbenzene, and xylenes, approved methods (e.g., EPA SW-846 8021B, SW-846 8260) are not only recommended but are insisted upon for regulatory issues. Polynuclear aromatic hydrocarbons (PAHs) may be present in condensate, and evaluation of condensate contamination should include the use of other test methods (EPA SW-846 8270, SW-846 8310) provided that the detection limits are adequate to the task of soil and groundwater protection. Generally, at least one analysis may be required for the most contaminated sample location from each source area. Condensate releases in nonsensitive areas require analysis for naphthalene only. The analysts should ensure that the method has detection limits that are appropriate for risk determinations. 

In addition to acute toxicity tests, two standard chronic toxicity test methods are widely accepted by various regulatory agencies the seven-day Ceriodaphnia survival and reproduction test and the 21-day Daphnia reproduction test. 

The following are the major subjects of the book the various institutions, agencies, and programs involved in chemicals regulation (Chapter 2). The data for hazard assessment (Chapter 3) and the hazard assessment process, i.e., identihcation and characterization of the various toxicological effects and the associated test methods (Chapter 4). Standard setting for threshold effects (Chapter 5) and non-threshold effects (Chapter 6). Exposure assessment (Chapter 7) and risk characterization (Chapter 8). Regulatory standards set by various bodies (Chapter 9) and combined actions of chemicals in mixture (Chapter 10). 

Department strengthen the science base in toxicology develop and validate improved testing methods and provide information about potentially toxic chemicals to health regulatory and research agencies, the scientific and medical communities, and the public. 

Issue Industry and the regulatory authorities need to agree on (1) what constitutes a valid efficacy claim for each product type, (2) the test methods used to generate data in support of these claims and (3) a test method development strategy and plan for the most critical areas where methods are inadequate or missing. 

Various techniques have been proposed and developed over the years for the examination of fetuses for potential teratogenic effects of exogenous substances such as pharmaceutical candidates (1-8). Each method has its advantages and disadvantages (see below). For regulatory testing purposes (9, 10), a balance between rapidity and thoroughness is paramount. Microdissection meets this requirement. 

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