Finding of Emergency Section 5204 , Occupational Exposures to Respirable Crystalline Silica Business Meeting : December 14 , 2023 Page 10 of 36
granite workers or in former coal miners where , in one study , 10 % advanced to progressive massive fibrosis over an average of 22 years . The investigators concluded that silicosis from exposure to artificial stone RCS is aggressive and exhibits rapid disease progression in a high proportion of affected individuals .
A 2023 toxicological study by Chandnee Ramkissoon , et al . reported that the hazardous volatile organic compounds ( VOCs ) phthalic anhydride , styrene , benzene , ethylbenzene and toluene are released during cutting , grinding , polishing and other tasks required during fabrication of artificial stone products . 36 Phthalic anhydride made up 26 %– 85 % of the total VOC content of artificial stone emissions . Phthalic anhydride and styrene are respiratory irritants . These VOCs are released from the resins that make up the binding agent in artificial stone .
A 2022 toxicological study by Chandnee Ramkissoon , et al . found that 80 % of the mass of dust produced from dry-machining artificial stone under controlled conditions consisted of RCS , whereas cutting natural stone ( granite ) produced RCS concentrations ranging from 4 % to 30 % of the dust mass . 37 Both artificial stone and granite produced high concentrations of very fine particles (< 1 µ m ). More than 90 % of the dust particles had diameters ranging from 0.19 to 0.83 µ m , making them uniquely able to reach the deep lung . In this same study , researchers found that artificial stone particles showed more irregular shapes compared to natural stone dust particles , with sharp edges and fractures along the surfaces ( see Figure 2 in Ramkissoon , 2022 ). This could increase the rate at which artificial stone RCS particles cause cell damage in the lungs , which produces scarring and , eventually , silicosis .
A 2020 toxicological study by Mariella Carrieri , et al . evaluated the RCS content of bulk dust in artificial stone compared to granite . 38 The percent RCS in the dust was 53 % for artificial stone and only 8 % for granite , indicating that a greater percentage of particles generated by artificial stone would penetrate much more readily into the lungs , compared to dust generated from granite .
A 2016 toxicological study by Cristina Pavan , et al . found that RCS particles generated from artificial stone were more reactive and fibrogenic ( likely to break into fibers , which are more
36
Ramkissoon C , et al . Engineered Stone Fabrication Work Releases Volatile Organic Compounds Classified as Lung Irritants . Annals of Work Exposures and Health ( 2023 ); 67 ( 2 ) 288 – 293 . https :// pubmed . ncbi . nlm . nih . gov / 36239208 /. Accessed August 16 , 2023 .
37
Ramkissoon C , et al . Characterisation of dust emissions from machined engineered stones to understand the hazard for accelerated silicosis . Nature Portfolio 12:42351 ( 2022 ). https :// www . nature . com / articles / s41598-022-08378-8 . Accessed August 16 , 2022 .
38
Carrieri M , et al ( 2020 )., Characterization of Silica Exposure . op . cit . https :// www . ncbi . nlm . nih . gov / pmc / articles / PMC7345731 / .