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Sorption ability of polymeric materials for medical purposes was studied with respect to the sterilizing gas - ethylene oxide - at 23, 35 and 55 degrees C. Sorption coefficients of ethylene oxide (EO) for the materials under study were calculated on the basis of results. Investigation of the kinetics of desorption of EO from the polymeric materials for medical purposes has shown that its content changes exponentially depending on the time of degassing. However, the lines in the 1g Q/Q0 - tau coordinates show a sharp break which testifies to a change in the mechanism of the process determining the character of the mentioned dependence. In the first region, corresponding to high concentrations and short periods of time, the determining process is diffusion while in the second region (low concentrations, long time intervals) - it is desorption of EO molecules most firmly bound to the polymer. Diffusion coefficients were calculated for the first region. The possibility of predicting the time periods of removing ethylene oxide from the polymeric materials was demonstrated for both stages on the basis of calculated diffusion coefficients and kinetic curves of degassing. Recommendations were given for the use of polymers for medical appliances and apparatuses.

Insecticido-repellent mixtures sprayed on clothes, nets etc. are useful as a means of protection against attack by bloodsucking arthropods. These sprays provide repellence of insects sensitive to the repellent and kill those that are only weakly repellent sensitive. Combined formulae for aerosols including repellent DETA and the synthetic pyrethroid neopynamin ("Neorepellent-2") or sumithrin ("Sumirepellent") were proposed. The composite sprays were studied in an olfactometer fleas (X. cheopis) and under practical conditions by treating clothes with 7-15 g of mixture per 1 m2. The composite sprays gave 100% repellence for fleas and mosquitoes, 80-50% repellence for simuliids, 65-70% repellence for ceratopogonids and tabanids, 90-95% for ticks, and they killed 100% of insects having contacted treated surface. As regards Ixodes ticks, "Sumirepellent" was more effective than "Neorepellent-2" and caused irreversible paralysis. Toxicological tests showed the composite sprays to be safe in broad-scale practical use provided that measures of precaution were kept.

Results of investigation of toxicity of ethylene oxide (EO) entering the organism by routes other than inhalation (subcutaneous, intramuscular, intraperitoneal, intravenous) have demonstrated that the substance causes intoxication characterized by polytropic effect on many vitally important organs and systems. The changes in most of the indices under study show a phasic character and dose-time dependence. In both the acute and chronic effect, impairment of the state of the nervous system, the liver, kidney, blood and reactivity of the organism come to the foreground. After one single entrance, EO becomes manifest as a low-risk (class 4) compound (Limac for subcutaneous, intraperitoneal and intravenous routes being 5.0, 0.5 and 1.0 mg/kg, respectively); after repeated exposure as a high-risk (class 2) compound (Limchr for subcutaneous and intraperitoneal route being 1.0 and 0.1 mg/kg, respectively). In comparison with the subcutaneous route, the intravenous and intraperitoneal routes are more dangerous. The obtained parameters of EO toxicometry can be used as a basis for the calculation of safe levels of residual quantities of the compound in articles for medical use.

A formula for the filling of aerosol containers has been elaborated on the basis of a mixture of hexachlorocyclohexane (HCH) gamma isomer and tetrametrin, in a ratio 3:1 with the addition of furniture varnish NC-62 to produce the film, Khladon 11/12 (5050) served as propellent. The study of the process of crystallization of the insecticides on the surface of the film has shown that the effectiveness of insecticidal varnishes is the higher, the smaller the size of the crystals and the easier they can be removed from the surface of the film. This can be achieved by including tetrametrin along with HCH gamma isomer in the formula. The testing of the insecticidal activity and toxicity of aerosols prepared according to the elaborated formula has demonstrated high insecticidal activity of the composition with respect to synanthropic cockroaches and fairly low toxicity with respect to warm-blooded animals.