Resin poisoning

Plant resins, poison ivy, poison oak, poison sumac Metals (nickel or gold in jewelry)... 

Balucani, M., and D.D. Zellers. 1964. Podophyllum resin poisoning with complete recovery. /. Am. Med. Assoc. 189(8) 639-640. Bargman, H. 1988. Is podophyllin a safe drug to use and can it be used during pregnancy Arch. Dermatol. 124(11) 1718-1720. 

One of the resin poisons of considerable importance in the South African uranium plants is the very stable cobalti-cyanide complex, or series of complexes, which form as a result of leaching the ore with cyanide solutions. These are used for the extraction of gold before the final leach with sulphuric acid for uranium extraction. The cobalti-cyanide complex can sometimes be removed from the resin by treatment with 2M potassium thiocyanate solution. This is expensive and not always satisfactory under plant conditions since it is beheved that several different compounds are responsible, some of them polymeric complexes and some are retained by the resin to a greater extent than others. The most satisfactory procedure is to prevent the absorption of cobalti-cyanide by removing it from the ore. This is accomplished by means of a water wash of the ore between cyanida-tion and sulphuric add leaching. However, cobalt poisoning remains a problem at some of the South African refineries, particularly that at West Rand. The resin is in fact usually replaced when its cobalt content reaches 2-5 per cent. ... 

Silica often acts as a type of resin poison, but its effect is more mechanical than chemical. Dehydration of the silica, or its production from dissolved silicic acid, leads to its deposition upon the resin beads and to some extent in the interior of the beads. This occurs particularly near the point of entry of the feed solution to the column. This may result in restriction of flow rate or even a complete obstruction to flow, if the voids between beads become filled. In addition, the silica coating upon the resin beads causes the diffusion rate to be reduced. This gives an apparent reduction in the resin capacity. Some minerals give sulphuric acid leach liquors with a higher concentration of silica than others, e.g. the ore from the Mary Kathleen plant in Australia. The reason for this has been stated to be the high degree of silica breakdown which has occurred in the mineral owing to the action of a-radiation. ... 

Everest, D. A., Napier, E. and Wells, R. A. Resin poisons in ion-exchange recovery processes. Proc. 2nd Int. Conf. on the Peaceful Uses of Atomic Energy, Geneva, 1958. Paper 101. 

The Du Pont HaskeU Laboratory for Toxicology and Industrial Medicine has conducted a study to determine the acute inhalation toxicity of fumes evolved from Tefzel fluoropolymers when heated at elevated temperatures. Rats were exposed to decomposition products of Tefzel for 4 h at various temperatures. The approximate lethal temperature (ALT) for Tefzel resins was deterrnined to be 335—350°C. AH rats survived exposure to pyrolysis products from Tefzel heated to 300°C for this time period. At the ALT level, death was from pulmonary edema carbon monoxide poisoning was probably a contributing factor. Hydrolyzable fluoride was present in the pyrolysis products, with concentration dependent on temperature. 

Shipping vitamin D in crystalline or resin form should be done in containers marked appropriately to indicate the material is toxic by DOT standards. Its proper DOT labeling is DOT Hazard Class 6.1, poisonous. Waste material should be burned or placed in an appropriate landfill. 

In more recent years two new types of antifouling composition have been developed, using organometallic compounds as poisons. In one type, based chiefly on vinyl resin and organotin compounds (e.g. tributyltin fluoride), the poison and resin form a solid solution. As the poison dissolves from the surface of the film, more poison diffuses from deeper in the film to... 

The major chemical problem met in ion-exchange practice is the fouling or poisoning of the anion resins by organic matter. The various counter measures deployed include pre-flocculation, oxidation of the organic material, the use of specially developed resins, and treatment of the fouled resins by brine and/or hypochlorite. 

Dithiobenzoic acid metal complexes, 2, 646 colours, 2, 646 Dithiobiuret metal complexes, 2, 640 Dithiocarbamates chelating resins mineral processing, 6,826 Dithiocarbamic acid metal complexes, 2,585 amine exchange, 1,428 photographic emulsions, 6,98 nickel poisoning, 6,768 tellurium(Il) complexes photothermography, 6,121 Dithiocarbazic acid metal complexes, 2,803 Dithiocarbimic acid metal complexes, 2,588 Dithiocarbimic acid, cyano-metal complexes, 2,808 Dithiocarboxylic acids metal complexes, 2,646 Dithiodiacetic acid metal complexes, 2, 806 Dithiodiketones... 

Substances Hazardous to Health, See also Toxic chemicals, 19, 138, 140 Substitution, 133 Sulphur, 30 Sulphur dioxide first aid, 280, 306 physical properties, 306 physiological properties, 69, 71, 304, 305 precautions, 305, 306 vapour pressure, 305 Suppression, 135 Surface area effects, 50, 199 Symbols for dangerous substances, 446, 452 Synthetic lubricants, 159 Synthetic resins, 172 Systemic poisons, 19, 77... 

To assess the utility of this resin, we chose to employ it in the evaluation of the heterogeneity of a commercial polymer-entrapped Pd(OAc)2 precatalyst, Pd-EnCat, also sold by Reaxa. This precatalyst was designed with the goal of providing a heterogeneous catalyst that would allow simple removal of palladium from reactions (24-26). PVPy and QTU were first used as poisons in the Heck reaction of iodobenzene and n-butyl acrylate in DMF using PdfC as the palladium... 

Not all solid poisons will likely be nseful in all media. Many polymeric resin-based poisons swell differently in various solvents. In one solvent, all the sites may be accessible, whereas in others, as little as a 1% of the sites, those on the external surface, for example, may be available. 

Arsenic compounds can be very effective corrosion inhibitors but their toxicity, ineffectiveness in hydrochloric acids above 17% active and in the presence of H S, and their ability to poison refinery catalysts has limited their use (148). Epoxy resins have been coated onto metal surfaces and cured with a polyamine to reduce corrosion (149). 

The most frequent causes of allergic contact dermatitis in the United States include plants (poison ivy, poison oak, and poison sumac), metallic salts, organic dyes, plastic resins, rubber additives, and germicides.74 The most common skin patch test allergens found to be positive in patients along with potential sources of exposure are shown in Table 32.1.75 In patients with occupational contact dermatitis who were skin patch tested, the common allergens included carba mix, thiuram mix, formaldehyde, epoxy resin, and nickel.76... 

On 1st January 2000 the new regulations re-classifying isocyanates as resin components came into force. According to the new definitions TDI prepolymers with a clear TDI proportion of 1-7% must be rated as poisonous and provided with risk memoranda R23, R40 and R42/43. Clear TDI proportions of 0.1-1% must be rated as harmful... 

For thousands of years, humans have devised practical uses for chemicals found in nature. Egyptian priests depended on natural oils and resins as antibiotics in mummifying human and animal remains. South American Indians prepared plant extracts to tip their arrows with fast-acting poison. The ancient Chinese discovered the secret of silk, magically converting an insect s cocoon into an elegant textile. 

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