Article | A world with Silica vol. 4

When a coreless induction furnace is lined with a dry silica mass, even though the exposure time for the installers is short, significant concentrations of Respirable Crystalline Silica (RCS) can be produced, which makes the use of Personal Protective Equipment (PPE) mandatory, and in particular, Respiratory Protective Equipment (RPE).

These brief notes that we have been publishing from INSERTEC, arise as a result of the new legislation on RCS. This legislation, beyond the regulated requirements, requires an adaptation and modernization of working methods in the sectors that handle these materials. Thus, the refractory installation must incorporate techniques that guarantee the maximum safety of the installers, who in turn must have the required training to adequately carry out their tasks to meet the needed legislation.

Today the use of PPE and RPEs is essential, considering that the legislation itself cites their use in order to guarantee the minimum exposure of workers to RCS.

However, prevention of a known danger should command a collective solution between all connected parties that can only then bring the needed optimised solution. With this in mind refractory providers, furnace manufacturers and end users must advance technological and process automation improvements in the coming years. Although the challenge is technically complex it must be seen has unavoidable, needing the development of equipment and working methods that avoid, as far as possible, the close proximity and contact of the installers with the dry material.

As technological advances develop (which we will refer to in the next chapter), the proper use of PPE and RPEs, as well as other complementary measures, is key. We highlight some, in a non-exhaustive way:

Segregated areas for day and work cloths
- It is emphasized the need for separation since contamination is often invisible to the eye

Ensure that only needed personnel can enter the work area
- Barriers and hazard warning indicators to be installed

Ventilation and extraction of the furnace and work area
Use of adapted furnace fume extraction, dedicated fixed point extraction or mobile extraction is needed.

Disposable / Single Use Coveralls
- As complete body cover as practical including head hood should be targeted
- Elasticated cuffs, ankles and face ports
- After use should be removed with minimum dust generation (water dowsing) and be safely disposed of in designated contaminated waste zones.

Security boots
- Like any job in foundry.
- They should not be cleaned with methods that put dust into suspension, and in no case by blowing. Ideally, they should be vacuumed.

- Like any job in foundry.

Respiratory Protection Equipment
- Probably the most critical protection
- Local regulations must always be followed based on specific exposure levels, frequency of exposure and physical limitations for individual installers and or site access.
- Consideration to disposable, disposable valved, half masks, air flow and oxygen assisted masks must be consulted.
- Due to the dangers of RCS then at least FFP3 dust filtration grades should be selected.
- Face fitting types, respirator maintenance and connected training should be part of the considerations to ensure effectiveness.

In order to protect the installer and other personnel the cleaning of any reusable equipment should be done by vacuum or atomised water. Never use any form of compressed or blown air.

In short, the new personal hygiene practices will configure the new work scenario in demolition and reconstruction of furnaces, to which will be added the technological advances that will necessarily be developed and implemented.