Reconstituted stone or engineered stone have some health and safety issues to solve. By the end of 2011 the reconstituted stone and engineered stone industry will have solved the serious health and safety issues. Truth is that everyone knows the dangers the Styrene and BTEX can pose to health, nevertheless in 2010 most manufacturers have either invested in equipment or have evaluated it's effects.
What is Styrene?
Styrene is a chemical which is one of the main components of polyester resin, actually most resin manufacturers use it as a solvent, and can represent 30-40% of the mass of polyester resin. It's very volatile and is used to manage the viscosity levels of the resin, in theory the smaller the grain used to make the engineered stone the less viscosity is needed in the resin. This means it has to be more liquid to guarantee an even spread through the whole mixture, this is done by adding more styrene to the polyester resin, in the production of resin the last phase is actually setting the viscosity index, and this is done by adding styrene.
What is BTEX?
BTEX is really benzene, toluene ethyl-benzene and xylene's, active components found in resin.
Why is styrene and BTEX health hazards?
People who are exposed to styrene in it's original form may suffer serious health hazards, namely affecting the central nervous system, headaches, dizziness, fatigue and difficulty in concentrating may be some symptoms. Styrene has been classified by the IARC (International Agency for Research on Cancer) as a potential human carcinogen.
BTEX as Styrene is also considered a potential human carcinogen.
The health hazard can be minimized if the levels of Styrene and BTEX are reduced, the acceptable levels are <50mg/kg for Styrene and <6mg/kg for BTEX
So how are manufacturers dealing with this potential health hazard?
Their are two ways to actually solve this problem, the first is use eco resin which has low levels of Styrene and BTEX, although the resin is much more expensive, it will increase product costs to the end user.
The other way is to buy equipment to extract the Styrene and BTEX from the product. Actually the manufacturers have two problems to solve, as the final product carries Styrene and BTEX, but also the sludge has the same components.
Technically at 55ºC Styrene will evaporate, so basically the manufacturing plants will need to install staging warehouses at 55ºC for slabs and blocks. In addition they'll need special equipment to retreat the hazardous chemicals from the air and give it the proper disposal, a block may need up to 30 hours, although a slab may take fewer hours, nevertheless it is a big investment moneywise and space.
Regarding chinese manufacturers, I figure they're behind in this matter, most of them are just adapting to CE markings, next they'll have to face the Styrene and BTEX issue to survive in International markets. Being that in general the Chinese manufacturing systems use more resin in the composition of the engineered stone, this problem is more serious for them currently.