Perhaps one of the most common violations of EHS regulations in Thailand is related to works in confined space. In most violation cases, the factory owner does not understand what is confined space or aware that works performed within their factory shall be treated as works in confined space condition. Since violation of standards for works in confined space will eventually turn into a tragedy, which happens so often in the country, being constantly seen in  media coverage at least 2-3 times a year.

One of the most shocking case happened in June 2017. A group of interns at a food processing factory was given a tour of the plant, and the plant’s environmental officer who guided  them around had worked at the factory for less than six months. At wastewater treatment plant tour, one female intern suddenly fell into a four-meter-deep wastewater treatment pond. The plant’s environmental officer, who was leading the tour, was the first person to jump into the pond to rescue her, but they were both lost consciousness. Another three staffs then rushed to the wastewater treatment area to try to pull the two victims out from the pond, but they also became unconscious and fell into the pond. The three staffs, together with the female intern and the environmental officer, were later confirmed to be dead due to inhalation of toxic gas produced by the wastewater and lack of oxygen. Police investigation confirmed that the wastewater treatment area had to be an area restricted from entering because it falls under the definition of “confined space” but the fact that such area was never restrict was a violation of the law. Later, the factory manager was charged with negligence over the death of five people.

Figure: the pond where intern fell (source: Khaosod Online Newspaper)

In general, a confined space can be defined as a fully or partially enclosed space that is not primarily designed or intended for continuous human occupancy, has limited or restricted entrance or exit, or a configuration that can complicate first aid, rescue, evacuation, or other emergency response activities. Confined space can represent a risk for the health and safety of those who enter due to: 1) its design, construction, location or atmosphere 2) the materials or substances in it 3) work activities being carried out in it, or 4) mechanical, process and safety hazards present. Common misunderstanding is that confined space must be at underground. In fact, confined spaces can be both below or above ground and found in almost every workplace. A confined space, despite its image associated with the name, is not necessarily small. Examples of confined spaces include silos, vats, hoppers, utility vaults, tanks, water supply towers, sewers, pipes, access shafts, truck or rail tank cars, aircraft wings, boilers, manholes, pump stations, digesters, manure pits and storage bins. Ditches and trenches may also be a confined space when access or egress is limited. Barges, shipping containers and fish holds are also considered as potential confined spaces. Hazards in confined spaces can include:

  • Poor air quality: There may be an insufficient amount of oxygen for workers to breathe or the air in such area might contain a poisonous substance that could make the workers sick.
  • Hazards from asphyxiants that are gases which can become so concentrated that they displace oxygen in the air such as argon, nitrogen, and carbon monoxide.
  • Chemical exposures due to skin contact or ingestion as well as inhalation of ‘bad’ air.
  • Fire hazard: There may be an explosive/flammable atmosphere due to flammable liquids or gases or combustible dusts which if ignited would lead to fire or explosion.
  • Process-related hazards such as residual chemicals, release of contents of a supply line.
  • Physical hazards – noise, temperature, radiation, vibration, electrical, and inadequate lighting.
  • Safety hazards such as moving parts, structural hazards, engulfment, entanglement, slips, falls.
  • Vehicular and pedestrian traffic.
  • Shifting or collapse of bulk material.
  • Barrier failure resulting in a flood or release of free-flowing solid or liquid.
  • Visibility such as smoke particles
  • Biological hazards – viruses, bacteria from fecal matter and sludge, fungi, or molds.


Regulations on working conditions in confines space

The regulation that designates standards for working in confined space is the Ministerial Regulation Stipulating the Standards for Management and Operation of Safety, Occupational Health, and Working Environment Relating to Confined Space B.E. 2562 (2019). This regulation gives definition of the term “confined space” as “location where access is limited and is not designed for regular continuous work and has dangerous conditions or dangerous atmosphere such as tunnels, caves, wells, pits, basements, vaults, oil tanks, fermenters, tanks, silos, pipes, furnaces, containers or other similar condition” and gives definition of the term “hazardous atmosphere” as “atmosphere conditions that may expose employees to harm and fall under any of the following:

  • Oxygen content is less than 5 percent or more than 23.5 percent by volume.
  • Contains flammable or explosive gas, vapor or aerosol more than 10% of the minimum concentration of each chemical that may be flammable or explosive (lower flammable/explosive limit).
  • Contains flammable or explosive dust; which has a concentration equal to or greater than the minimum concentration of each type of combustible or explosive dust (minimum explosible concentration)
  • Having the concentration value of each chemical substance exceeding the standard prescribed under the Ministerial Regulation Stipulating Standards for the Management and Operation of Occupational Safety and Working Environment Related to Hazardous Chemicals
  • Any other conditions that may endanger human body or life as announced by the Director General.”

The regulation also prescribes criteria for factory owners to follow that can be summarized below:

  • Factory owner shall assess the hazardous conditions of confined spaces, keep record of such assessment and prepare a sign with clearly visible message “Confined Space. Dangerous. Entry is Prohibited” to inform those who may enter such areas. The sign must be at the entrance and exit of all confined spaces.
  • No one should be allowed to enter confined spaces, unless 1) such a person has no respiratory disease, heart disease, or other disease that doctor deems entering confined space may be dangerous for the person with the disease and 2) the person is trained on working safety in confined spaces.
  • Factory owner shall arrange a measurement and record such measurement results and then assess the condition of confined spaces before allowing for workers to work in the confined spaces. In case any hazardous condition is found, those who are working in the confined space must evacuate or corrective measures must be taken such that the condition in the confined space is no longer hazardous. Measurement records and measures taken must be kept for inspection by official for at least one year. At least one trained person must be assigned as “helper,” who is with proper equipment for rescue and is able to contact workers at all time.
  • When hazardous condition still exists in confined spaces, working in such area must require personal protective equipment (PPE) and be supervised by trained personnel who has duties as follows:
      • prepare an action plan, work hazard prevention plan and emergency rescue plan; and inform such plans to workers by announcement or by written notification.
      • clarify and rehearsal individual duties and responsibilities, working procedure and hazardous prevention method in accordance with the plans.
      • supervise the employees’ use of personal protective equipment and inspect such equipment so that it is in the ready-to-use condition.
      • in the event that employees may be in danger, immediately order a temporary cessation of work.
  • Factory owner should prohibit workers from smoking in confined space, provide adequate and suitable equipment for work, provide suitable fire extinguisher system and prevent specific types of work in confined space such as work that generates heat or sparks – for example; welding, burning, riveting, drilling and sanding as well as work that uses volatile substances, toxic substances or flammable substances.
  • The regulation also stipulates that a factory owner must give written permission to trained worker every time to work in confined space. The permission must have, at least, details of the work such as location, working day and time, task to perform, name of workers, name of supervisor, name of helper, hazardous condition and procedure for prevention and rescue, hazard assessment result, safety measures, personal protective equipment and rescue equipment, name of person who gives permission, medical examination results of workers. Such permission documents must be kept for record.
  • Factory owner must arrange training on working in confined space for every worker who performs in confined space. The training record must be kept such that official can check at all time.

Aside from the regulation, as lessons from many accidents of this kind, general recommendations for factory owner are:

  1. It is important that those who work in confined space recognize the associated dangers.
  2. It should be a safety rule that if someone falls into a confined pit, pipe or tank, those who goes down to help have to at least wear a breathing apparatus to avoid inhaling the poisonous gas.
  3. It is also important to prevent this kind of accident with installation of safety equipment such as rail, non-slip floors, ladder to climb up from the well, or even signal bell.
  4. Remember the Murphy’s law “Anything that can go wrong will go wrong.”
  5. Factory owner must understand the importance of safety equipment.

The regulation, updated in 2019, aims to fix such problems. With this regulation, we will see if the situation will get better or not.