CS Gas Research Articles

Medical implications of the operational use of CS spray by police forces

Medical implications of the operational use of CS spray by police forces

An appropriate use of CS spray?

An appropriate use of CS spray?

Beam formation at the Munich atomic beam source

A Stern–Gerlach atomic-beam ion source (ABS) with an electron cyclotron resonance (ECR) ionizer and a Cs gas target as charge exchange units will replace the Munich Lamb–Shift polarized hydrogen source. The goal is to achieve intense negative beams of polarized H− and D− of high brightness for injection into the 14 MV MP tandem accelerator and beam intensity of about 2 μA on the target. At the entrance of the ECR ionizer the observed intensity of the neutral beam of polarized atoms is 6.4±0.4×1016 H/s, equivalent to 10 particle/mA before ionization. Comparing beam transport calculations with beam intensity measurements under various conditions allows a consistent description of the beam formation in the ABS with respect to the degree of dissociation (≃80%), peaking (≃1.6), beam absorption (≃40%), and pumping speeds to be made.

An Electron Microscopic Study on Cytoplasmic Organelles of the Cilicated Cell in Tracheal Epithelium in o-Chlorobenzylidene malononitrile (CS)gas exposed rat.

An Electron Microscopic Study on Cytoplasmic Organelles of the Cilicated Cell in Tracheal Epithelium in o-Chlorobenzylidene malononitrile (CS)gas exposed rat.

CS gas exposure in a crowded night club: the consequences for an accident and emergency department.

A case is reported of deliberate release of CS gas (O-chlorobenzylidene malononitrile) in an enclosed space and the consequences for an accident and emergency department.

Are CS sprays safe?

Are CS sprays safe?

The use of CS spray in the mentally ill

CS sprays are now being widely used by police in the UK. Concerns are being expressed regarding the toxicity of this substance and some of the situations in which it is being used. This is the first reported case in the UK of CS spray being used to restrain a mentally ill person in police custody. It raises important issues regarding the welfare of mentally ill people who happen to find themselves in contact with the police. There is a need for open debate, specific guidelines and a system of monitoring the use of CS in such situations.

Characterization of Lachrymators by Ambient Temperature Ion Mobility Spectrometry

Abstract Current methods for the detection of tear gas residues require extensive sample preparation before spectral measurement. This contrasts with the present work in which a new detection method for the active ingredients of CN (α-chloroacetophenone), CS (2-chlorobenzylidenemalononitrile), and pepper sprays (capsaicin and crude pepper extracts) based on ambient temperature, atmospheric pressure ion mobility spectrometry has been developed. The minimum determinable limits were: α-chloroacetophenone 0.1 μg, 2-chlorobenzylidenemalononitrile 25 mg, and cayenne pepper 5 mg. These limits were dependent on the vapor pressure, proton affinity and electronegativity of the target molecule.

Analysis of the1H and13C{1H} NMR Spectral Parameters of the Tear Gases α-Chloroacetophenone, Dibenz[b,f][1,4]oxazepine, and 2-Chlorobenzylidene Malononitrile

The 1H and 13C{1H} NMR spectra of the tear gases α-chloroacetophenone, dibenz[b,f][1,4]oxazepine and 2-chlorobenzylidene malononitrile were recorded in CDCl3, CD2Cl2 and (CD3)2CO and analysed. Assignments of the resonances were confirmed by homonuclear and heteronuclear correlation spectroscopy. Detailed 1H spectral parameters were determined by iterative analysis. The conformations of dibenz[b,f][1,4]oxazepine and 2-chlorobenzylidene malononitrile were determined on the basis of the long-range coupling constants 4J(α,ortho), 5J(α,meta) and 6J(α,para). Use of the 1H spectral parameters of dibenz[b,f][1,4]oxazepine for simulation of a reference spectrum is demonstrated for a test sample.

Acute mass burns caused by o-chlorobenzylidene malononitrile (CS) tear gas

The use of tear gas in controlling riots has been an accepted practice in many countries for the past four decades. In a recent event, a large quantity of tear-gas canisters were used during a situation of unrest in a Hong Kong Refugees' Detention Centre. We report 96 cases of acute burn injury as an unpredicted side effect of o-chlorobenzylidene malononitrile (CS) tear gas. There were 47 females and 49 males with an age ranging between < 1 to 51 years. These burns were categorized as minor burns, with the total body surface area (TBSA) ranging from 1 to 8 per cent with mean percentage of 3. Most of the patients sustained superficial or partial-skin thickness injuries. Only two patients were admitted to the Prince of Wales Hospital Burns Centre because of deeper burns; debridement and skin grafting was required in one of them. The mechanism of burn injury was due to the flame generated from the grenade explosion, direct contact between the hot canister and the victim's skin, and the effect of the chemical powder inside the canisters when it splashed onto the victim's body. We suggest that the noxious transient effects of tear gas are underestimated, furthermore varying cutaneous effects and deep burns may result from its uncontrolled use during riots. There is a continuing need to reassess the potential toxic effects of CS tear gas as a riot control agent and to debate whether its future use can be condoned under any circumstances.

Charge distributions and coagulation of radioactive aerosols

The self-charging of radioactive aerosols will be reduced by background ions, such as those produced by radioactive gases. The sources of these background ions and their production rates are specified for a reactor containment atmosphere during a possible nuclear accident. Previous theory is extended to calculate the charging of a polydisperse radioactive aerosol. Gaussian approximations to charge distributions on an aerosol of a given size, and are shown to give a good representation of the exact numerical charge distributions of a Cs aerosol at normal temperatures, and also for highly radioactive aerosol containing 131I in a containment atmosphere. Extensive calculations are performed for charge-induced modifications to Brownian coagulation rates between steady-state size distributions of these radioactive aerosols, and also between small-sized radioactive aerosol and larger (non-radioactive) aerosol. The results show considerable enhancements of the coagulation rates between large and small-sized aerosol, but also a strong suppression of coagulation between large particles. Rate modifications calculated using the Gaussian approximations are generally close to the exact values. Time-dependent calculations for a monodisperse α-decaying aerosol reveal enhancements in coagulation rates even when the average charge on the aerosol is positive. Our results are relevant to behaviour in a dusty plasma.

Poisons centre will monitor cases

EDITOR,--Jean-Paul Yih's concern about the identification and management of injuries to the eye caused by O-chlorobenzylidine malononitrile (CS) gas1 is reflected by the number of inquiries about such injuries received by the National Poisons Information Service (London). In 1994, 354 emergency inquiries about CS gas were received from health care professionals throughout Britain. In some circumstances differential diagnosis of the chemical is easy, but a recent inquiry to the service concerned an incident in …

One minute wisdom. All you need to know about CS gas.

The ambulance driver came into the eye hospital that night and asked: ‘Will you see a patient I've got in the ambulance? He's been sprayed in the face with CS gas.’ Helpfully, he added: 'He’s having breathing difficulties.’

CS gas—implications for the anaesthetist

Although the use of CS gas is illegal in the UK, an occasional patient exposed to its effects may be seen. We report the problems experienced with the anaesthetic management of such a patient.

Mutagenicity evaluation of riot control agent o-chlorobenzylidene malononitrile (CS) in the Ames Salmonella/microsome test.

o-Chlorobenzylidene malononitrile (CS), a riot control agent, was evaluated for its possible mutagenic activity in the Ames Salmonella/mammalian microsome mutagenicity test. Five histidine-deficient (His-) mutant tester strains of Salmonella typhimurium--TA97a, TA98, TA100, TA102 and TA104--were used. The liquid preincubation procedure was used with metabolic activation (presence of S9 mixture) and without metabolic activation (absence of S9 mixture). For the experiments with metabolic activation, three different concentrations of S9 fraction (supernatant of Aroclor 1254-induced rat liver homogenate at 9000 g)--5%, 15% and 30% in S9 mixture--were used. Along with mutagenic activity, CS was also evaluated for cytotoxic activity in all the five tester strains of Salmonella typhimurium, both in the presence and absence of S9 mixture. The mutagenic and cytotoxic activities of CS were assessed by counting the His+ revertant colonies and by counting the microcolonies (His-, auxotrophs in the background lawn), respectively, and the respective mean values were compared with the relative negative (solvent) control. A dose range of 12.5-800 micrograms plate-1 for CS did not induce a mutagenic response either in the presence or absence of S9 mix. No change in the negative mutagenic response of CS has been observed even in the presence of an elevated level of S9 fraction in the S9 mix. A dose of 200 micrograms plate-1 for CS was found to be cytotoxic by decreasing the surviving cells as well as His+ revertant colonies; however, the effect was reduced in the presence of an elevated level of S9 fraction in the S9 mix.

The design of a radiocarbon muprobe for tracer mapping in biological specimens

Biological scientists use radioisotopes to label and subsequently monitor specific molecules within living systems. We aim to improve on conventional methods of imaging 14C tracers, in both sensitivity and resolution, by combining a new scanning-beam ion source generating C − secondary ions with our AMS system. Our measurements, including that of the generation of sufficient C − ions to the quantity of tissue sputtered, demonstrate that the radiocarbon muprobe is feasible, and we expect its sensitivity to be 1 14C label atom in 2000. We have employed the negative ion production enhancing effect of surface caesiation, investigating the potential of a Cs vapour spray for this purpose. As suitable Cs + ion sources are unavailable, the muprobe will feature a Cs spray to compensate for the lack of primary beam surface caesiation, in conjunction with a 0.2 μm spot Ga + beam.

Carbon Monosulfide Chemistry. Reactivity and Polymerization Studies

Abstract Carbon monosulfide can be generated by photolysis, thermolysis, or discharges of CS2. We have found a high voltage AC discharge works well for production of synthetic quantities of CS. This method yields a mixture of mainly CS and CS2 with small amounts of S8 and C3S2 A stream of CS gas about 85% pure can be obtained if this mixture is passed through a -112°C trap. The ground state of CS is X1 Σ+, and its spectroscopy is somewhat unique due to the similar energy levels of the first excited electronic configuration interspersed with the vibronic levels of the second excited state. The reactivity of CS is quite interesting. It will react with Lewis acids and Bronstead acids as well as Lewis bases. It is particularly reactive with halogens, basic amines and thiols, hydrogen halides, electron rich acetylenes, sulfenyl chlorides, and diazo compounds. This range of reactivity will be discussed with the aim of understanding reaction mechanisms and modes of attack. Another very favorable reaction is self...

Interferometric observations of M42 at 1.3 CM

New interferometric observations of the central 4.5 deg of M42 have been made at 1.3 cm with the NRO Millimeter-Wave Array. Distribution of the radio source consists of two known components. One is centered on the Trapezium stars, and the other corresponds to the bright bar. The present map is compared with the distribution of the CS molecular gas (Hayashi et al., 1989), and it is found that the boundary of the ionized gas is well delineated by the CS ridge. This indicates that the ionized gas is distributed in a cavity of the molecular gas, as suggested by Sugitani et al. (1986). A comparison of the map with a 6-cm radio-continuum map (Johnston et al., 1983) indicates that the 6 cm distribution is more extended than the 1.3 cm distribution, except in the southern part of the bright bar. 9 references.

Chemistry and Toxicity of Tear Gases

The article presents a historical background on the use of tear gases in war and civilian riot control activity. The classification of chemical compounds used as irritants, and their structure - activity relationship established through different studies has been examined. A review of toxic effects which is different from irritancy of Adamsite, w- chloroacetophenone (CN), o-chlorobenzylidene malononitrile (CS) and Dibenz (b,f), [1, 4] - oxazepine (CR) has been presented.

The fate of 2-chlorobenzylidene malononitrile (CS) in rats

1. The fate of 3H-ring labelled, 14C-cyanide labelled and (14C = C) side chain labelled 2-chlorobenzylidene malononitrile (CS), 2-chlorobenzyl alcohol and 2-chlorobenzyl malononitrile (dihydro CS) in rats and isolated rat liver cells has been examined. 2. CS was administered both i.v. and i.g. to rats at doses from 0.08 to 159 mumol/kg and in most cases the greatest proportion of the dose was eliminated in the urine (44-100%). The principal urinary metabolites were 2-chlorohippuric acid, 1-O-(2-chlorobenzyl) glucuronic acid, 2-chlorobenzyl cysteine and 2-chlorobenzoic acid. Lesser amounts of 2-chlorophenyl acetyl glycine, 2-chlorobenzyl alcohol and 2-chlorophenyl 2-cyano propionate were identified. 3. The major urinary metabolite from 2-chlorobenzyl alcohol was 2-chlorohippuric acid (43%), 2-chlorobenzyl cysteine, 2-chlorobenzoic acid and 2-chlorobenzyl glucuronic acid were identified. 4. The products of dihydro-CS metabolism were 2-chlorophenyl acetyl glycine, 2-chlorophenyl 2-cyanopropionate and 2-chlorophenyl proprionamide. 5. Urinary thiocyanate levels increased with the dose of CS up to 159 mumol/kg. At 212 mumol/kg there was a large increase in the amount of thiocyanate produced (molar conversion: 21.5-29.9%). Similarly malononitrile, the hydrolysis product of CS, gave a dose related increase in urinary thiocyanate levels. However at a higher dose (212 mumol/kg) the molar conversion was greater than 60%. 6. The metabolism of CS by isolated rat liver cells confirmed the results in vivo but demonstrated a marked limitation of this preparation to form conjugates. 7. It is concluded that CS in vivo is hydrolysed mainly to 2-chlorobenzaldehyde which is then either oxidized to 2-chlorobenzoic acid for subsequent glycine conjugation, or reduced to 2-chlorobenzyl alcohol for ultimate excretion as 2-chlorobenzyl acetyl cysteine or 1-O-(2-chlorobenzyl) glucuronic acid. Malononitrile is converted to thiocyanate via the formation of cyanide.