Working in a confined space can present some specific dangers and those who are responsible for either doing the work or overseeing it have to make sure that they are aware of these risks. This is why it's important that all involved go through specific training, so that there is no confusion and everybody is clear about the challenges they face. In particular, the atmosphere in the confined space needs to be monitored and regulated and this is very carefully covered in the training. What do you need to think about here?
Understanding the Key Criteria
A confined space is only thought to be safe if the atmosphere within passes three crucial tests. Firstly, it has to have levels of flammable gas or vapour that are considered to be acceptable. Secondly, it must be largely free of airborne contaminants and lastly it has to have an oxygen level that is adequate for the workers in place.
One of the first tasks to perform will be the removal of any potentially flammable gases or vapours from the space and this is often purged by introducing nitrogen, which is an inert gas. It's very important to ensure that any vapours or gases are completely removed from the location to an area where they pose no extra risk. This will require equipment to be set up very carefully.
After the area has been purged it has to be tested again to prove that these gases or vapours have been eliminated. After that, a supply of fresh air has to be introduced before work can commence.
Mechanical ventilation systems have to be brought in where any confined space is not well ventilated. The mechanical system will bring in air from an uncontaminated area and must be positioned far away from any place where vapours or gases are being exhausted.
Types of Ventilation
Sometimes it will be necessary to employ a special type of ventilation known as "dilution." This will be even more important if certain types of contaminant are present in the space. For example, if asbestos may be a threat, then additional monitoring equipment needs to be brought in. A supervisor must also make sure that all equipment in use remains in good working condition and guard against equipment failure.
Working with Flammable Vapours and Gases
Government regulations clearly specify "acceptable" levels of flammable gases and vapours and these levels must be monitored to ensure that they always remain below the guidelines. Furthermore, ignition sources have to be carefully managed and these include open flames, electrical equipment or tools and anything that might produce a spark.
Why Training Is a Must
Training courses will go into great detail and elaborate on all of these policies and procedures and everyone involved should go through them before proceeding.