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Blast cleaning with silica sand and the health risks involved.
In the past, blast cleaning operations were done with silica sand abrasive. The word sandblasting originates from these days. Nowadays, people have come to realise that exposure to respirable crystalline silica dust during construction activities such as sandblasting and blast cleaning can cause a serious or even fatal respiratory disease, called Silicosis, a scarring and hardening of the lungs.
In the Netherlands and many other countries, it is forbidden to use blastcleaning abrasives, which contain more than 0,1% free silica. Silica sand abrasive contains much more free silica than 0,1 %, normally about 90%, but sometimes even up to 95% or higher. During the blast cleaning operation (sandblasting), the sand particles break down into very small micro-sized particles. These particles, smaller than 5-10 microns(µ) are inhaled and become embedded in the lung, causing respiratory problems, pulmonary silicosis (also called 'dust-lungs'), and eventually even death.
A good quality blast hood, with a filtered respirator, is considered to be enough protection for the blasters during sandblasting, however this is only partly correct. During blast cleaning operations with silica sand abrasive (sandblasting), large clouds of dust will arise in the surrounding air. A crystalline silica dust particle of 2 microns (µ) drops only 1 meter per 24 hours, during windless conditions. This means that the dust-clouds remain invisibly in the air for a long time, long after the sandblasting is finished.
When the blaster has to stop working for a while, for whatever reason and he takes off the blast hood, a large quantity of micro-sized silica dust will be deposited on the inside of the hood. When he then starts his sandblasting work again and he puts the hood back on, he will inhale an extreme dose of free silica dust instead of getting the protection he expected to get.
The risks for people in the vicinity of the sandblasting operation are even higher. Think of other workers on the sandblasting site, in the office etc. The dust-clouds can be spread-out by the wind and these people do not have any protection at all.
During the past years, many countries have established laws to prohibit the use of sand as an abrasive for sandblasting. In The Netherlands, sandblasting with silica sand abrasive has been forbidden already since 1956 and instead of sandblasting we now speak about gritblasting or abrasive blastcleaning
A high quality substitute blastcleaning abrasive for gritblasting is available: the renowned Eurogrit Aluminium Silicate blast cleaning abrasive (coalslag grit) contains less than 0,1% free silica, which makes it an approved blast cleaning abrasive for gritblasting in the entire world.
For further information about this subject, for all your inquiries for blast cleaning abrasives for gritblasting, for sound advise on all your abrasive questions, please do not hesitate to contact us. We will be glad to provide you with all necessary information.
Go safe - go Eurogrit!
For further information on sandblasting and silicosis you can have a look at:
www.osha-slc.gov/SLTC/silicacrystalline
www.cdc.gov/niosh/topics/silica/default.html
www.cdc.gov/niosh/homepage.html
www.cdc.gov/niosh/silicaw3.html
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