Ocular injuries from shake and bake methamphetamine labs

PURPOSE

To review ocular injuries resulting from "shake and bake" methamphetamine labs.

METHOD

Retrospective case series of 4 patients with ocular injuries sustained from "shake and bake" lab explosions.

RESULTS

Four men ages 20-39 underwent complete ophthalmologic examination after an injury from a "shake and bake" methamphetamine lab explosion.The mechanism of injury was initially misrepresented in each case; the physical findings were suggestive of thermal and alkali injury. Visual acuity ranged widely from 20/20 to light perception only. Treatment in the acute setting included irrigation, pH monitoring, and intraocular pressure lowering.

CONCLUSION

Methamphetamine production by means of the"shake and bake" method can result in combined thermal and alkali ocular injury. Patients who sustain this type of injury may not accurately report the mechanism of exposure. Increased awareness of this type of ocular injury may increase the rapidity of diagnosis, avoid early misdiagnosis, and ultimately improve outcomes.

Characterization of partially reduced graphene oxide as room temperature sensor for H2

Reduced graphene oxide (RGO) was synthesized under H(2)/Ar treatment from 100 °C to 900 °C. RGO-300 shows excellent sensitivity to H(2) and a dual sensing mode was observed. The balance between the chemical adsorption capacity and electronic conductivity, and the dominance of either electrons or holes are the key factors.

Accident investigation reporting deficiencies related to organizational factors in machinery space fires and explosions

Careful accident investigation provides opportunities to review safety arrangements in socio-technical systems. There is consensus that human intervention is involved in the majority of accidents. Ever cautious of the consequences attributed to such a claim vis-à-vis the apportionment of blame, several authors have highlighted the importance of investigating organizational factors in this respect. Specific regulations to limit what were perceived as unsuitable organizational influences in shipping operations were adopted by the International Maritime Organization (IMO). Guidance is provided for the investigation of human and organizational factors involved in maritime accidents. This paper presents a review of 41 accident investigation reports related to machinery space fires and explosions. The objective was to find out if organizational factors are identified during maritime accident investigations. An adapted version of the Human Factor Analysis and Classification System (HFACS) with minor modifications related to machinery space features was used for this review. The results of the review show that organizational factors were not identified by maritime accident investigators to the extent expected had the IMO guidelines been observed. Instead, contributing factors at the lower end of organizational echelons are over-represented.

Modeling solid thermal explosion containment on reactor HNIW and HMX

2,4,6,8,10,12-Hexanitro-2,4,6,8,10,12-hexaaza-isowurtzitane (HNIW), also known as CL-20 and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), are highly energetic materials which have been popular in national defense industries for years. This study established the models of thermal decomposition and thermal explosion hazard for HNIW and HMX. Differential scanning calorimetry (DSC) data were used for parameters determination of the thermokinetic models, and then these models were employed for simulation of thermal explosion in a 437L barrel reactor and a 24 kg cubic box package. Experimental results indicating the best storage conditions to avoid any violent runaway reaction of HNIW and HMX were also discovered. This study also developed an efficient procedure regarding creation of thermokinetics and assessment of thermal hazards of HNIW and HMX that could be applied to ensure safe storage conditions.

Experimental determination of self-heating and self-ignition risks associated with the dusts of agricultural materials commonly stored in silos

Agricultural products stored in silos, and their dusts, can undergo oxidation and self-heating, increasing the risk of self-ignition and therefore of fires and explosions. The aim of the present work was to determine the thermal susceptibility (as reflected by the Maciejasz index, the temperature of the emission of flammable volatile substances and the combined information provided by the apparent activation energy and the oxidation temperature) of icing sugar, bread-making flour, maize, wheat, barley, alfalfa, and soybean dusts, using experimental methods for the characterisation of different types of coal (no standardised procedure exists for characterising the thermal susceptibility of either coal or agricultural products). In addition, the thermal stability of wheat, i.e., the risk of self-ignition determined as a function of sample volume, ignition temperature and storage time, was determined using the methods outlined in standard EN 15188:2007. The advantages and drawbacks of the different methods used are discussed.

Determination of parameters used to prevent ignition of stored materials and to protect against explosions in food industries

There are always risks associated with silos when the stored material has been characterized as prone to self-ignition or explosion. Further research focused on the characterization of agricultural materials stored in silos is needed due to the lack of data found in the literature. The aim of this study was to determine the ignitability and explosive parameters of several agricultural products commonly stored in silos in order to assess the risk of ignition and dust explosion. Minimum Ignition Temperature, with dust forming a cloud and deposited in a layer, Lower Explosive Limit, Minimum Ignition Energy, Maximum Explosion Pressure and Maximum Explosion Pressure Rise were determined for seven agricultural materials: icing sugar, maize, wheat and barley grain dust, alfalfa, bread-making wheat and soybean dust. Following characterization, these were found to be prone to producing self-ignition when stored in silos under certain conditions.

Mitigation of TNT and Destex explosion effects using water mist

The effects water mist has on the overpressures produced by the detonation of 50 lb equivalent of high explosives (HE) TNT and Destex in a chamber is reported. The overpressures for each charge density were measured with and without mist preemptively sprayed into the space. A droplet analyzer was placed in the chamber prior to the detonation experiments to characterize the water mist used to mitigate the explosion overpressures. The impulse, initial blast wave, and quasi-static overpressure measured in the blast mitigation experiments were reduced by as much as 40%, 36%, 35% for TNT and 43%, 25%, 33% for Destex when water mist was sprayed 60s prior to detonation at a concentration of 70 g/m(3) and droplet Sauter Mean Diameter (SMD) 54 microm. These results suggest that current water mist technology is a potentially promising concept for the mitigation of overpressure effects produced from the detonation of high explosives.

Molecular simulation studies on chemical reactivity of methylcyclopentadiene

Molecular simulations are important to predict thermodynamic values for reactive chemicals especially when sufficient experimental data are not available. Methylcyclopentadiene (MCP) is an example of a highly reactive and hazardous compound in the chemical process industry. In this work, chemical reactivity of 2-methylcyclopentadiene, including isomerization, dimerization, and oxidation reactions, is investigated in detail by theoretical computational chemistry methods and empirical thermodynamic-energy correlation. On the basis of molecular simulations, an average value of -15.2 kcal/mol for overall heat of dimerization and -45.6 kcal/mol for overall heat of oxidation were obtained in gaseous phase at 298 K and 1 atm. These molecular simulation studies can provide guidance for the design of safer chemical processes, safer handling of MCP, and also provide useful information for an investigation of the T2 Laboratories explosion on December 19, 2007, in Florida.

Explosion protection for vehicles intended for the transport of flammable gases and liquids--an investigation into technical and operational basics

In Europe, the transport of flammable gases and liquids in tanks has been impacted by new developments: for example, the introduction of the vapour-balancing technique on a broad scale and the steady increase in the application of electronic components with their own power sources; furthermore, new regulatory policies like the ATEX Directives are being enforced in the European Union. With this background in mind, the present investigation aims to provide a basis for future developments of the relevant explosion protection regulations in the safety codes for the transport of dangerous goods (RID/ADR). Specifically, the concentration of gas in the air was measured under various practical conditions while tank vehicles were being loaded with flammable gases or liquids. These spot-test data were supplemented by systematic investigations at a road tanker placed in our test field. With respect to non-electrical ignition sources, a closer investigation of the effect of hot surfaces was carried out. With regard to improving the current regulations, the results of our investigation show that it would be reasonable to implement a stronger differentiation of the characteristics of the dangerous goods (gaseous/liquid, flashpoint) on the one hand and of the techniques applied (loading with and without vapour-balancing system) on the other hand. Conclusions for the further development of the current international regulations are proposed.

The simulation of air recirculation and fire/explosion phenomena within a semiconductor factory

The semiconductor industry is the collection of capital-intensive firms that employ a variety of hazardous chemicals and engage in the design and fabrication of semiconductor devices. Owing to its processing characteristics, the fully confined structure of the fabrication area (fab) and the vertical airflow ventilation design restrict the applications of traditional consequence analysis techniques that are commonly used in other industries. The adverse situation also limits the advancement of a fire/explosion prevention design for the industry. In this research, a realistic model of a semiconductor factory with a fab, sub-fabrication area, supply air plenum, and return air plenum structures was constructed and the computational fluid dynamics algorithm was employed to simulate the possible fire/explosion range and its severity. The semiconductor factory has fan module units with high efficiency particulate air filters that can keep the airflow uniform within the cleanroom. This condition was modeled by 25 fans, three layers of porous ceiling, and one layer of porous floor. The obtained results predicted very well the real airflow pattern in the semiconductor factory. Different released gases, leak locations, and leak rates were applied to investigate their influence on the hazard range and severity. Common mitigation measures such as a water spray system and a pressure relief panel were also provided to study their potential effectiveness to relieve thermal radiation and overpressure hazards within a fab. The semiconductor industry can use this simulation procedure as a reference on how to implement a consequence analysis for a flammable gas release accident within an air recirculation cleanroom.

[Stop the annual firework disaster--a plea for medical scientific associations to take a clear-cut position]

Every year people sustain serious injuries when they let off fireworks on New Year's Eve. Public education and protective eye wear do not solve this problem. Experience from other countries shows that the number of injuries decreases dramatically when fireworks are handled only by experienced specialists. Medical scientific associations are invited to promote a ban on ordinary citizens letting off fireworks and for fireworks to be reserved for firework specialists only.

Correlation between self-ignition of a dust layer on a hot surface and in baskets in an oven

Evaluation of self-ignition hazard of bulk materials requires experimental determination of self-ignition temperatures as a function of volume. There are two standardised methods: (1) determination of the self-ignition temperature of dust samples in oven and (2) measurement of the self-ignition temperature of a dust layer deposited on a hot surface. Sometimes, the sample behaviour during these tests makes the second method difficult to apply. The self-ignition phenomena in these two tests rely on the same principles. Their results are interpreted with the help of theoretical relations. The correlation described in this paper can be considered acceptable to deduce self-ignition temperature of a dust layer, based on results of self-ignition of the same dust in heating ovens, if the Biot number (alpha) can be estimated. Uncertainty on the correlation is near 30K. This uncertainty is on the same order of magnitude as the difference in the self-ignition temperature on a hot surface for thickness between 5 and 15 mm.

Numerical investigation of explosion suppression by inert particles in straight ducts

This paper is devoted to the mitigation of explosions in long galleries by means of an inert dust cloud. In practice, this technique bases on mounting shelves under the roof, on which the inert dust is distributed. This issue was numerically investigated in this research. The medium was assumed to be a two-phase mixture consisting of a fast flowing gas (representing the explosion) and a cloud of solid particles (representing the dust phase). The model makes use of the Eulerian-Lagrangian approach, where the solid particles are modelled as moving points, interacting with the gas flow. The objective was to analyse the suppression process and compare with experimental findings.

MIKE 3 versus HARTMANN apparatus: comparison of measured minimum ignition energy (MIE)

In this study, MIE values measured with two different explosion tubes, HARTMANN and MIKE 3, are compared. Generally, MIKE 3 apparatus provides MIE results, which are equal or lower to those measured with the HARTMANN apparatus; this is particularly true for the energy ranges between 1 and 10mJ and higher than 100mJ. Differences observed can modify samples classification according to their sensitivity to electrostatic ignition sources. Nevertheless, ignition of a dust cloud by an electrostatic discharge is complex, and implies a different mechanism from that occurring during MIE tests. Thus, it seems difficult to synchronise dust dispersion and spark triggering to obtain optimal concentration in the spark area. Moreover, spark characteristics such as duration or energy feeding rate of spark cannot reproduce exactly industrial-world ones. On this point, it is not possible to conclude if characteristics of MIKE 3 electric circuit, e.g., resistance and inductance, are more relevant than HARTMANN circuit ones.

[Firework injuries in Denmark in the period 1995/1996 to 2006/2007]

INTRODUCTION

The purpose of this study was to observe the occurrence and character of firework injuries on the two days around New Year in Denmark over the last decade.

MATERIALS AND METHODS

Since 1995/1996 all Accident and Emergency Departments in Denmark have registered all contacts where fireworks were the cause of injury on 31st December and 1st January. Data comprised hospital, sex, age, type of firework, diagnosis and final treatment. Follow-up and reminder by phone secured a 100% response rate. The total number of injured patients was 4,447.

RESULTS

The number of firework injuries on the 31st of December and 1st of January was reduced by half over the 12-year period. Furthermore, the number of firework injuries caused by illegal fireworks in 2006/2007 was only 10% of the number in 1996/1997. Only 8% of injuries on last New Year's Eve were caused by illegal firewoks compared to almost 50% at the beginning of the period. A similar halving is seen in serious injuries. Roughly one quarter sustained injuries to the eyes, one quarter to the head/neck and 38% to hands.

CONCLUSION

Firework injuries are now half of the level in 1996/1997. Injuries caused by illegal fireworks and serious injuries have shown a downward tendency throughout the period. The actual number of severe injuries from illegal fireworks is now only 10% of the level in the mid-1990s. This reduction can be attributed to preventive campaigns, greater knowledge of the risk of fireworks in general as well as legislation. Continued focus on preventive campaigns, control of fireworks for the general public and control of firework distribution to professionals is recommended.