Confined Space Entry Procedures

Introduction

A space with limited means of access and egress can be referred to as confined space. The confined space has characteristics that often that include limited means of access and egress, poor lighting, poor ventilation, and bad housekeeping, these all be associated at the time one, or maybe few of them can be associated with space considered confined space. Examples of confined space can be the interior of a storage tank, main hole, underground ducts, pit, well, or oil tankers where workers entered occasionally for maintenance work. The confined space itself is hazardous due to space constraints and also the risk for workers is increased due to the presence of hazards that often include dust or gases, asphyxiation, submersion in liquids, sharp edges electrocution, or entrapment.
Confined space accidents are of very serious concern in occupational safety and health due to high-risk consequences for both victims and the rescuers. Therefore, confined space entry procedures and safety protocols are highly recommended in all types of industries. Further, these procedures are enhanced by additional backing with precautions such as air quality testing, lockout & tagout procedure, induced ventilation, a deputation of confined space observers at the opening, PPEs, and predefined ERP (Emergency Rescue Plan).
In this article, we will discuss the Confined Space Entry Procedures in detail and explain all its important elements.

Identification of confined space Hazards

Before the start of any activity it is crucial to do hazard identification of the surrounding environment of confined space these hazards can be identified as under;

• Testing of oxygen level in the atmosphere around and in the confined space - it must be in the range of more than 19.5 % and not more than 23.5 %. Testing should be done at all levels entry point mid of the space and bottom of the confined space
• Combustible material or gases testing these tests includes CH4 fumes testing, gasoline fumes testing and hydrocarbons slush testing at the bottom
• Testing of toxic gases include hydrogen sulfide and carbon monoxide or any other toxic gas al all level of the confined space

These all tests must be done by an authorized person equipped with all necessary personal protective equipment and approved gas tester

Ventilation of confined space

The next step of the confined space entry procedure is the venting procedure in which the confined space is subjected to the removal of all toxic and hazardous gases. For this purpose multiple methods can be used - the most widely used method for venting confined pace is mechanical or induced ventilation of the confined space. This can be done by introducing fresh air into the tank from the bottom of the tank which ultimately flowers the concentration of confined space gases and forces them to leave the tank.
It is important to understand that sometimes we get desirable results at the opening of the tank but there are certain points within confined space where the flammable or toxic gases trap and become the cause of accidents if we do not complete venting properly. Therefore, every part of the confined space must undergo a vetting process. After ventilation of confined space, the hazard identification process must be repeated and ensure the results must be in an acceptable range.
Some important values associated with atmospheric testing are given below;

• Oxygen level more than 19.5% and not more than 23.5%
• Flammability must be lower than 10% lower flammable limit (LFL)
• Toxicity must be lower than 50% Permissible exposure limit (PEL)

Training

One of the most important elements of a confined space entry procedure is the training of workers and rescuers. Because an unskilled or untrained worker can convert the safe situation into a harmful environment, similarly a trained rescuer can increase the chances of life-saving whenever an accident or emergency happens. It is the responsibility of the employer or contractor to provide the necessary training and equipment before expecting confined space work. The training for workers can be used for equipment and PPEs during work in confined space, how to communicate and coordinate in an emergency situation. While for the rescuer, emergency rescue related training and onsite simulation can be recommended.

Confined Space Entry Permit

Confined space permit is a formal document that can be between client and contractor or in some cases it can be between departments within an organization. The work permit contains details of all pre-entry requirements, a list of employees involved in the activity, and the ERP of the activity.
It is the document that ensures facilitation in the communication of logout and tag or some time isolation of energy supply from confined space.
One of the most widely used works permits systems is the PTW system which has a comprehensive layout for access permission to work in confined space.

Pre-Entry Requirements

Even when the workers' supervisor have a work permit he should not allow the worker to enter into confined space before compliance with the below pre-entry requirements;

• Rescue team or a member of the team available on the site or outside confined space
• Two-person should allow working inside confined space
• One competent person should monitor the work inside a confined space
• All hazardous gases must be within the permissible limit
• Oxygen level must be within the allowable limit
• Continuous testing of atmosphere facility
• Appropriate lighting facility to work in confined space

Monitoring the work

Below are the important parameter which needs to be tested and monitored during work within confined space;

• Percentage of oxygen in the working atmosphere
• The concentration of flammable gases in the working atmosphere
• Toxicity limit
• Other potential hazards

Some, other non-potential hazards which need to be monitored in confined space outline below;

• The noise level during work in confined space
• Electric hazard and electric backup
• The temperature of the confined space
• Exposure to a mechanical hazard

The confined space attendant or observer must have a proper template where all these values are recorded and used to make decisions if any emergency situation prevails.

Box up Confined Space Task

Once the work in confined space is completed or shift has been closed the team leads or supervisor must instruct workers to box up the task and make the space free of any hazard originating due to work or any material remaining after work. Good housekeeping after completing a task or closing shift can prevent many accidents on the next day.
The permit must be closed after completing the box up the task with the closing signs of the authorized person. In some cases, the work is done or closing of confined space permit is pre-requirement of the closure of logout therefore be careful while closing permit to entry confined space.

For some more interesting information on health, safety and environment below blogs are recommended;

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