A Proposed Incipient Fire and Toxic Gas Caution and Warning for Shuttle
Incipient fire and toxic gas caution and warning system for space shuttles
Krupnick, A. C.↗
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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Effect of acetylsalicylic acid and ascorbic acid on oxygen toxicity
Acetylsalicylic and ascorbic acids effects on mice susceptibility to oxygen toxicity, discussing in vitro sensitivity of red cells to hydrogen peroxide
Jefferson, D.↗
Some aspects of the toxicity of formose sugars
Dietary effects of formose sugars ingestion, investigating toxic mechanisms involved
Chermside, H. B.↗
Lead: Aspects of its ecology and environmental toxicity
An analysis of lead toxicity in the Hawaiian environment was conducted. It was determined that lead enters the environment as an industrial contaminant resulting from the combustion of leaded gasoline. The amount of lead absorbed by the plants in various parts of the Hawaiian Islands is reported. The disposition of lead in the sediments of canals and yacht basins was investigated. The methods for conducting the surveys of lead content are described. Possible consequences of continued environmental pollution by burning leaded gasoline are discussed.
Siegel, S. M.↗
Handbook for estimating toxic fuel hazards
Computer program predicts, from readily available meteorological data, concentration and dosage fields downwind from ground-level and elevated sources of toxic fuel emissions. Mathematical model is applicable to hot plume rise from industrial stacks and should also be of interest to air pollution meteorologists.
Dumbauld, R. K.↗
Apollo Soyuz mission, toxic gas entered cabin during earth landing sequence
A postflight analysis is presented of the sequence which caused toxic gas to enter the cabin during repressurization for 30 seconds from manual deployment of the drogue parachutes at 18,550 feet to disabling of the reaction control system at 9600 feet. Results and conclusions are discussed.
Source record↗
The effects of forced air flow and oxygen concentration on flammability, smoke density, and pyrolytic toxicity
The question is posed whether forced air flow should be incorporated into flammability tests as a relevant variable. A test apparatus is described which permits tests to be conducted on small test specimens in a forced flow which is (continuously) variable over flow velocities from zero to 300 feet per minute (1.52 m/s). The effects of air-flow rate and oxygen concentration on flame propagation rate, maximum smoke density, and pyrolytic product toxicity were measured for a single material and were statistically evaluated. Regression analysis was used to graph the resulting relationships. It is concluded that air velocity is an important variable for laboratory flammability testing.
Sauers, D. G.↗
Relative toxicity of pyrolysis products of some cellular polymers
Twelve samples of cellular polymers were evaluated in the course of developing test methods for toxic materials characterization. Six samples were flexible polyurethane foams, three were rigid polyurethane foams, two were high density rigid foams, and one was a modified polyimide foam. Some effects of formulation variables are discussed.
Hilado, C. J.↗
A large hemispherical chamber for fire toxicity tests
The paper describes an 84-liter chamber for fire toxicity tests consisting of an upper hemispherical dome section with a diameter of 533 mm, made of clear polymethyl methacrylate and a lower cylindrical base section 190 mm deep, made of cast aluminum. The chamber is designed to expose 36 mice, 8 rats, 4 rabbits or combinations of smaller numbers of two or three species simultaneously to the gaseous products of pyrolysis or combustion. The chamber does not appear to be suitable for screening purposes because its large size introduces operating costs and problems which reduce its cost effectiveness.
Hilado, C. J.↗
A bibliography of published information relevant to fire toxicity
A bibliography containing 883 references in the field of fire toxicity is presented to assist in literature searches to help reduce human fire hazards.
Hilado, C. J.↗
A technique for extracting blood samples from mice in fire toxicity tests
The extraction of adequate blood samples from moribund and dead mice has been a problem because of the small quantity of blood in each animal and the short time available between the animals' death and coagulation of the blood. These difficulties are particularly critical in fire toxicity tests because removal of the test animals while observing proper safety precautions for personnel is time-consuming. Techniques for extracting blood samples from mice were evaluated, and a technique was developed to obtain up to 0.8 ml of blood from a single mouse after death. The technique involves rapid exposure and cutting of the posterior vena cava and accumulation of blood in the peritoneal space. Blood samples of 0.5 ml or more from individual mice have been consistently obtained as much as 16 minutes after apparent death. Results of carboxyhemoglobin analyses of blood appeared reproducible and consistent with carbon monoxide concentrations in the exposure chamber.
Bucci, T. J.↗
Some possible reference materials for fire toxicity tests
Suitable reference materials need to be selected in order to standardize any test method. The evaluation of cotton, polyethylene, polyether sulfone, polycarbonate, polystyrene, and polyurethane flexible and rigid foams as possible reference materials for the University of San Francisco/NASA toxicity screening test method is discussed.
Hilado, C. J.↗
Studies with the USF/NASA toxicity screening test method - Exercise wheels and oxygen replenishment
Continuing efforts to improve the University of San Francisco/NASA toxicity screening test method have included the addition of exercise wheels to provide a different measure of incapacitation, and oxygen replenishment to offset any effect of oxygen depletion by the test animals. The addition of exercise wheels limited the number of animals in each test and doubled the required number of tests without any significant improvement in reproducibility. Oxygen replenishment appears to have an effect on survival in the last 5 minutes of the 30-minute test, but the effect is expected to be similar for most materials.
Hilado, C. J.↗
The use of a behavioral response system in the USF/NASA toxicity screening test method
Relative toxicity data on the pyrolysis effluents from bisphenol A polycarbonate and wool fabric were obtained, based on visual observations of the behavior of free-moving mice and on an avoidance response behavioral paradigm of restrained rats monitored by an instrumented behavioral system. The initial experiments show an essentially 1:1 correlation between the two systems with regard to first signs of incapacitation, collapse, and death from pyrolysis effluents from polycarbonate. It is hypothesized that similarly good correlations between these two systems might exist for other materials exhibiting predominantly carbon monoxide mechanisms of intoxication. This hypothesis needs to be confirmed, however, by additional experiments. Data with wool fabric exhibited greater variability with both procedures, indicating possibly different mechanisms of intoxication for wool as compared with bisphenol A polycarbonate.
Hilado, C. J.↗
Fire resistivity and toxicity studies of candidate aircraft passenger seat materials
Fire resistivity studies were conducted on a wide range of candidate nonmetallic materials being considered for the construction of improved fire resistant aircraft passenger seats. These materials were evaluated on the basis of FAA airworthiness burn and smoke generation tests, colorfastness, limiting oxygen index, and animal toxicity tests. Physical, mechanical, and aesthetic properties were also assessed. Candidate seat materials that have significantly improved thermal response to various thermal loads corresponding to reasonable fire threats as they relate to in-flight fire situations, are identified.
Fewell, L. L.↗
Studies with the USF/NASA toxicity screening test method - Oxygen concentrations with various test conditions
Continuing efforts to increase the versatility of the USF/NASA toxicity screening test method have included the use of different test conditions in order to simulate various fire environments. The use of air flow at flow rates of 16 to 48 ml/sec maintains oxygen concentrations above 19 percent throughout the 30 min exposure period, compared to above 16 percent without forced air flow. These levels of oxygen are well within the tolerance range of mice, and approach the oxygen levels found in many real fire situations. Proposed minimum oxygen levels based on experience with rats are unduly restrictive on the use of other species such as mice, and tend to eliminate the cost savings which may more than justify the selection of mice.
Hilado, C. J.↗
Reproducibility of toxicity test data as a function of mouse strain, animal lot, and operator
The toxicity screening test method developed at the University of San Francisco was evaluated for reproducibility. The variables addressed were strain of mouse, lot of animals, and operator. There was a significant difference in response between Swiss Webster mice and ICR mice, with the latter exhibiting greater resistance. These two strains of mice are not interchangeable in this procedure. Variation between individual animals was significant and unavoidable. In view of this variation, between-lot and between-operator variations appear to have no practical significance. The significant variation between individual animals stresses the need for average values based on at least four animals, and preferably values based on at least two experiments and eight animals. Efforts to compare materials should be based on the evaluation of relatively simple responses using substantial numbers of animals, rather than on elaborate evaluation of single animals
Hilado, C. J.↗
Screening materials for relative toxicity in fire situations
Results of screening tests of materials for relative toxicity under specific sets of conditions are presented. Variations in the material, in lab animals, and in the test presently permit identification of major rather than minor differences among materials. Correlation with relative performance in real fire situations is based on a limited number of comparisons.
Hilado, C. J.↗