Prevention against carbon monoxide poisoning emanating from burning coal briquettes - Generation rate of carbon monoxide and ventilation requirement.

Carbon monoxide (CO) poisoning accidents occur every year in Japan, most of which are caused by the incomplete combustion of fuel, such as gasoline, light oil, and coal briquettes. To prevent CO poisoning in workers, it is essential to reduce the CO concentration in a working environment below the criteria threshold through ventilation. Although proper ventilation requirements for enclosed spaces are estimated from the generation rate of air pollutants, there is no empirical research evaluating the CO generation rate of coal briquettes.

Analytical method using SEM-EDS for metal elements present in particulate matter generated from stainless steel flux-cored arc welding process.

Welding fumes (WFs) can cause occupational pneumonoconiosis and other diseases in workers. WFs have complex chemical composition and morphology depending on the welding conditions. The WF surface is a key factor affecting those diseases.

Features of the Japanese Industrial Safety and Health Act: some key points regarding the organization of safety and health management.

The Japanese Industrial Safety and Health Act was first enacted in 1972. The purpose of this Act is to secure the safety and health of workers in the workplace, as well as to facilitate the establishment of a comfortable work environment. To fulfill these purposes, the Industrial Safety and Health Act aims to clarify the responsibility system in the workplace and to promote proactive efforts by both employers and employees to maintain safety and health in the workplace.

"Purchase survey" of respiratory protective equipment as a follow-up on the national certification system in Japan.

Since respiratory protective equipment (RPE) are essential for the workers who are occupationally exposed to harmful airborne substances, it is necessary to complete a strict certification test on RPE. In Japan, Technology Institution of Industrial Safety (TIIS) is responsible for the RPE certification and examines the RPE submitted by the manufactures to make an admission decision with the national standards. However, the certification system cannot ensure the quality of the RPE after the shipping because some RPE may deteriorate during the distribution process or the storage period at retail stores.

Decline of the performance of a portable axial-flow fan due to the friction and duct bending loss of a connected flexible duct.

Objectives: In a job site, a portable fan is often used to ventilate a confined space. When a portable fan is applied to such a space, the actual ventilation flow rate must be accurately estimated in advance because the safety level of contaminant and oxygen concentrations in the space will determine the ventilation requirements. When a portable fan is used with a flexible duct, the actual flow rate of the fan decreases due to the friction and duct bending loss of the duct.

Generation rate and particle size distribution of wood dust by handheld sanding operation.

Objectives: The International Agency for Research on Cancer (IARC) and Japan Society for Occupational Health (JSOH) classified wood dust as a human carcinogen. Former studies have suggested that sanding with a portable sander is one of the processes that are liable to cause highest exposure to wood dust. However, the wood dust by sanding operation has not been investigated sufficiently.

An empirical study on the wake around a squatting worker in a confined space.

Objectives: When an air current flows from behind a worker, the contaminant level in the breathing zone may increase due to the wake around the worker. Researchers have been investigating about this wake, and much knowledge has been provided about the wake that appears around a standing worker. However, the wake around a squatting worker has not been addressed.

Generation rate of carbon monoxide from CO2 arc welding.

Objectives: CO poisoning has been a serious industrial hazard in Japanese workplaces. Although incomplete combustion is the major cause of CO generation, there is a risk of CO poisoning during some welding operations. The aim of the present study was to evaluate the generation rate of CO from CO2 arc welding under controlled laboratory conditions and estimate the ventilation requirements for the prevention of CO poisoning.

[Airflow equation of a slot hood by the least square method].

Objectives: In designing a local exhaust ventilation (LEV) system, the exhaust airflow rate which will produce the required control velocity at the capture point must be predicted properly. Conventionally, the airflow requirements for LEV hoods have been calculated using Dalla Valle's equation. Although Dalla Valle's equation is a simple and convenient formula for LEV design, it is known that the airflow rate predicted by the equation does not always coincide with actual exhaust airflow rate.

Gaseous contaminant distribution in the breathing zone.

Conventionally, the "breathing zone" is defined as the zone within a 0.3 m (or 10 inches) radius of a worker's nose and mouth, and it has been generally assumed that a contaminant in the breathing zone is homogeneous and its concentration is equivalent to the concentration inhaled by the worker. However, several studies have mentioned that the concentration is not uniform in the breathing zone when a worker is close to the contaminant source.

Measuring exposed magnetic fields of welders in working time.

The assessment of the occupational electromagnetic field exposure of welders is of great importance, especially in shielded-arc welding, which uses relatively high electric currents of up to several hundred amperes. In the present study, we measured the magnetic field exposure level of welders in the course of working. A 3-axis Hall magnetometer was attached to a subject's wrist in order to place the sensor probe at the closest position to the magnetic source (a cable from the current source).

Generation rate of carbon monoxide from burning charcoal.

Charcoal, often used as cooking fuel at some restaurants, generates a significant amount of carbon monoxide (CO) during its combustion. Every year in Japan, a number of cooks and waiters/waitresses are poisoned by CO emanating from burning charcoal. Although certain ventilation is necessary to prevent the accumulation of CO, it is difficult to estimate the proper ventilation requirement for CO because the generation rate of CO from burning charcoal has not been established.

Tracer gas evaluations of push-pull ventilation system performance.

A push-pull ventilation system is effective for hazardous material exhaustion. Although a push-pull ventilation system has advantages over a local exhaust hood, some laborious adjustments are required. The pertinence of the adjustments is uncertain because it is difficult to evaluate the performance of a push-pull ventilation system quantitatively.

Efficiency of a tool-mounted local exhaust ventilation system for controlling dust exposure during metal grinding operations.

In general, control of metal dust from hand-held disk grinders is difficult because such respirable dust tends to disperse in every direction around the grinding wheel and cannot be captured effectively by a conventional exhaust hood. The author described the application of a custom-made tool-mounted local exhaust ventilation (LEV) system attached to a hand-held disk grinder, and by laboratory experiments assessed its effectiveness at dust control. The effectiveness of the LEV for dust control was assessed by determining the respirable dust concentration around the grinding wheel during metal surface grinding with and without the use of the LEV.