This case study concerns our capability in undertaking risk assessment relating to occupational hygiene and in doing so, working closely with the client as part of an integrated solution to a problem, challenge, task or risk in a remote setting.
We were required to undertake an occupational hygiene risk assessment of an operation to remove old paint and rust from a 20 metre run of 36″ pipework prior to re-painting. This task involved blasting off the old paintwork from the steel pipe. Our role in the design and implementation of the work, from a medical services perspective, meant that we were part of an integrated solution, which gave lower costs, lower environmental impact and significantly lower risk to the health, safety and wellbeing of employees undertaking the work, or in the vicinity of the work.
The old paint contained lead. Erecting and dismantling a habitat would be required to protect others working in the vicinity, from the airborne contaminants. This would be time consuming and involve extra controls as personnel would be deemed to be working within a confined space.
Conventional blasting with Garnet was expensive, and also ran the risk of individuals engaged in the task inhaling contaminants above the exposure limit. Engineering controls in the form of local exhaust ventilation (LEV) would be expected. LEV management is notoriously difficult to manage effectively. Blasting with Garnet was also noisy and introduced the hazard of hand arm vibration for those operating the blasting equipment.
The proximity of the compressors in a relatively tight space and the routing of compressor hoses increased the safety risk. Due to the hazards associated with noise and vibration, greater rotation of those engaged in the work was required, which meant increased personnel wearing Respiratory Protective Equipment (RPE) which is costly in itself.
An innovative solution:
A less conventional approach was to use Sponge blasting equipment. This is a dry low dust process which requires minimal containment measures due to the nature of the process. The sponge media is re-usable and contains different sizes and grades of abrasives (or none), which can be used on surfaces ranging from the toughest to the most sensitive.
The Sponge-Jet system offered a fast, dry, clean, safe and flexible alternative to industrial surface preparation. The pipe work was large and relatively straight, so the kit could be easily set up. It appeared to be a cost effective alternative with a reduced Health and Safety risk compared to traditional wet blasting.
Sponge media is open-celled, water based polyurethane impregnated with abrasives. As a result it has several inherent cost, time and money saving benefits. The pliant nature of Sponge media allows its particles to flatten on impact exposing the abrasive. After leaving the surface, the media constricts, pulling and encapsulating what would normally have become airborne contaminants. The Sponge blasting system consists of the Sponge-Jet media feed units, Sponge-Jet media classifiers and a variety of different Sponge-Jet sponge media designed to offer a dry, low dust, low rebound, reusable abrasive or non-abrasive surface preparation system. There are several types of sponge grades and we elected to use red sponge as it was best for the type of surface preparation we required. It would also be less aggressive on the actual pipe work being blasting.
This was at the time a very new technique and there was little experience of previous use in an oil and gas environment. Access to the equipment was available and training in its use was minimal.Back to Case Studies