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Engineer’ Angle | Dangers in confined work space

Published:Sunday | August 5, 2018 | 12:00 AMAldane Stennett
A man standing in a confined space where he works,
Aldane Stennett
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The topic of confined space as it relates to safety is hardly discussed in Jamaica, even though it is of extreme importance in several aspects of the working environment.

A basic definition of confined space is one that:

a) Is large enough for an employee to enter and perform assigned work.

b) Is not primarily designed or intended for continuous human occupancy.

c) Has limited or restricted entrance or exit, or a configuration that can complicate first aid, rescue, evacuation, or other emergency response activities.

Confined spaces can be found in different types of industries, facilities and locations.

Some examples of exposure in the Jamaican workplaces that meet the criteria of confined space include silos, hoppers, storage bins, vats, tanks, truck tankers, sumps, wet or dry wells, pits, septic tanks, pipes, boilers, utility vaults, manholes, shafts, aircraft wings, and ditches.

The health and safety risks associated with confined spaces are generally very high because of the limited means of entry and exit that make escape difficult.

The fact that these spaces are not designed for continuous human occupancy, and in many situations contain physical hazards (exposed energised electrical equipment, huge rotating fan blades, etc, or atmospheric hazards areas commonly associated with low oxygen levels or poisonous gas) further complicate emergency circumstances.

 

TRAGIC CASES

 

Jamaica has had some very tragic cases resulting from work in confined spaces.

A well-documented case occurred on June 24, 1904 at West India Electric Company-Bog Walk Hydropower Station.

Sixty-one men went into a cast-iron pipe (tube) of a turbine to remove silt and debris. The water level inside the pipe began to rise due to a failure in the dam.

Recognising the perilous situation, the workers began to retreat, resulting in the escape of 28 of the men while 33 died from drowning with their bodies mutilated after being washed into the turbine.

Hazards relating to confined space know no borders. According to a NFPA Xchange report last year, four workers from Bangkok died from atmospheric condition emanating from a sewer pit while preparing to clean it.

We in Jamaica also cite recent cases of atmospheric hazards that result in the premature death of our workers.

A research was conducted into accidents related to confined space in Jamaica over the period 2005 - 2017 and the following was revealed.

At least 17 Jamaican workers have lost their lives, amounting to an average of at least one death per year in 11 accidental confined-space events.

Four of these 11 events resulted in the death of two or more persons.

Six other workers were reported injured and hospitalised in these accidents.

The average age of those succumbing to confined space hazard is approximately 32 years old.

About 36 per cent of these confined-space accident events involved multiple fatalities.

These accidents occurred in works of construction, utility service, agriculture, food and drinks manufacturing, and medical facility property maintenance

The spaces involved in these accidents were industrial process and storage vessels, excavated spaces, construction equipment, septic pit and spaces of nature (caves).

Approximately 53 per cent of the fatalities were due to workers exposure to atmospheric hazards inherent to the space or introduced to the space as a result of the work being undertaken.

The remaining 47 per cent were attributed to physical hazards associated with the spaces. Specifically, engulfment by solid flowing materials (soil, sugar) accounted for 29 per cent of the deaths, while entrapment and collapsing of the spaces contributed to 18 per cent of the fatalities.

Confined-space fatalities for the most part, occur due to persons' inability to recognise confined spaces and the associated hazards.

From worldwide study, it was shown that complacency and familiarity of environment have played parts in accidents attributed to confined spaces. Research on the subject highlighted that:

Eighty-nine per cent of confined-space fatalities occurred with jobs authorised by supervisors, and 80 per cent of fatalities happened in locations that had been previously entered by the same person who later died.

Sixty per cent of confined-space deaths occurred as a result of ill-conceived rescue mission, where persons attempted to rescue those already trapped or injured.

Hazardous atmospheric condition contributed to 40 per cent of confined-space fatal accidents in the United States.

It should be emphasised that the dangers of confined spaces cannot be taken for granted. The fact that the frequency of catastrophies that are associated with certain operations, areas or activities are low, should not reduce the priority of the treatment.

Therefore, it is imperative that confined-space hazards be evaluated for each entry with means established to effectively eliminate or control the hazards.

To achieve this, management and health and safety practitioners must implement a confined-space programme covering the elements of best practises at workplaces.

- Aldane Stennett is a registered professional engineer with more than 28 years of industrial experience. Send questions and comments to, editorial@gleanerjm.com or jie@cwjamaica.com. You may also leave your comments for the JIE's Technical Committee at our Facebook page: Jamaica Institution of Engineers - JIE.