EU OSHA Bilbao

28 January 2015

Italian Initiative on Artificial Stone and Silica

Ludovica Malaguti Aliberti and Marco Mecchia

Center of Chemical Substances – National Institute of Health

CSC Istituto Superiore di Sanità

Italian Workers’ Compensation Authority - INAIL

Part 2 Exposure to crystalline silica in factories for the production of kitchen countertops using artificial stone (Italy)

photos by Azzone, Bisio, Scibelli and Compagnoni

Number of measured data

item/plants

Resp. fraction (mg/m3) Resp. Quartz (mg/m3) Respirable Quartz (%)

Percentile value Percentile value Percentile value

10th 50th 90th 10th 50th 90th 10th 50th 90th

Sawing and Milling

182/88 0.09 0.44 1.43 0.005 0.030 0.180 1.1 8.2 22.5

Kernelling, charring and scabbing

26/17 0.26 0.61 3.04 0.010 0.150 0.830 1.4 22.2 48.3

Impact drilling and chiselling

203/35 0.09 0.62 1.41 0.010 0.050 0.290 1.7 8.6 41.2

Machine grinding

54/33 0.200 0.65 3.56 0.004 0.030 0.490 0.9 7.1 19.3

Manual grinding

102/49 0.21 0.89 3.27 0.005 0.040 0.490 0.6 6.2 21.1

TOTAL - manufacture, processing and work natural stone, stonemasonry

892/271 0.11 0.60 1.91 0.010 0.050 0.340 1.4 9.9 30.0

Exposure data in processing NATURAL stone (Germany 1995-2004)

Number of measured data

item/plants

Resp. fraction (mg/m3) Resp. Quartz (mg/m3) Respirable Quartz (%)

Percentile value Percentile value Percentile value

10th 50th 90th 10th 50th 90th 10th 50th 90th

Sawing and Milling

182/88 0.09 0.44 1.43 0.005 0.030 0.180 1.1 8.2 22.5

Kernelling, charring and scabbing

26/17 0.26 0.61 3.04 0.010 0.150 0.830 1.4 22.2 48.3

Impact drilling and chiselling

203/35 0.09 0.62 1.41 0.010 0.050 0.290 1.7 8.6 41.2

Machine grinding

54/33 0.200 0.65 3.56 0.004 0.030 0.490 0.9 7.1 19.3

Manual grinding

102/49 0.21 0.89 3.27 0.005 0.040 0.490 0.6 6.2 21.1

TOTAL - manufacture, processing and work natural stone, stonemasonry

892/271 0.11 0.60 1.91 0.010 0.050 0.340 1.4 9.9 30.0

>0.1

≤0.1

≤0.05

≤0.025

BGIA – Report 8/2006e

QU

AR

TZ C

ON

TEN

T

natural stone

Quartz (crystalline silica) content in rocks .

QU

AR

TZ C

ON

TEN

T

natural stone

. and artificial stones

RCS exposure in factories for the production of kitchen countertops using artificial stone

Facilities investigated in Italy Natural and artificial stones (raw materials) are sourced from Italy and abroad, and then cut and finished by a team of craftsmen

Respirable Crystaline Silica (RCS) exposure monitoring results have been published in three papers:

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3. Azzone M., Bisio E., Scibelli A. (2014). Intervento di vigilanza ‘Lavorazione di marmi tecnici’. Network Italiano Silice – Inail. Simposio ‘Silice libera cristallina: fra dibattito scientifico e buone prassi’. Roma, 22 maggio 2014.

1

1. Bartoli D., Banchi B., Di Benedetto F., Farina G., Iaia T., Poli C., Romanelli M., Scancarello G., Tarchi M. (2012). Silicosis in employees in the processing of kitchen, bar and shop countertops made from quartz resin composite. Ital. J. Occup. Environ. Hyg., 3(3), p.138-143.

2

2. Candido D., Compagnoni R. (2013). Esposizione a silice libera cristallina durante la lavorazione di materiali lapidei artificiali. Atti 8° Seminario Contarp, edizioni Inail.

• 22 stone finishing factories (60 workers) :

- 14 factories use only natural stones (31 workers) - 8 factories use both natural and artificial stones (29 workers)

Bartoli et al., 2012

1. Research on workers’ health (60 workers)

2. Measurements of RCS exposure (2 factories)

Chest X-rays according to ILO-BIT: 1 case of SILICOSIS among the 31 workers in the 14 facilities where only natural stones were used 7 cases of SILICOSIS (1 severe case) among the 29 workers in the 8 facilities where both natural and artificial stones were used

1. Monitoring conducted by the USL (local health authority) of Empoli and the University of Florence

RCS exposure in factories for the production of kitchen countertops using artificial stone

Surface processing and finishing

include the following operations:

• Dressing

• Brushing

• Sanding

• Bush hammering

• Rolling

• Polishing

Polishing machine

These operations take place mainly through the use of semi-automatic machines (wet dust suppression )

photo by Compagnoni

RCS exposure in factories for the production of kitchen countertops using artificial stone

These operations take place mainly through the use of semi-automatic machines (wet dust suppression )

Activity Factory

Concentration (mg/m3)

Respirable Dust Respirable

Quartz

Polishing (band polishing machine) A

0.45 0.041

Slab cutting (+ manual dressing) 4.92 0.059

Slab cutting

B

0.38 0.027

0.40 0.029

Polishing (+ manual dressing) 0.60 0.046

Polishing 0.42 0.027

Pantograph engraving 0.40 0.011

0.27 0.012

average sampling time Bartoli et al., 2012

>0.1

≤0.1

≤0.05

≤0.025

RCS exposure in factories for the production of kitchen countertops using artificial stone

Dry polishing photo by Compagnoni

RCS exposure in factories for the production of kitchen countertops using artificial stone

Surface processing and finishing

include the following operations:

• Dressing

• Brushing

• Sanding

• Bush hammering

• Rolling

• Polishing

Dry cutting, grinding and polishing are performed using handheld angle grinders

Activity Factory

Concentration (mg/m3)

Respirable Dust Respirable

Quartz

Dressing (granite and artificial stone) A 4.30 >0.360

2.00 >0.360

Dressing (granite and artificial stone) B

0.82 0.215

6.28 >0.520

4.59 >0.290

Dressing (granite) 5.77 0.049

Dry cutting, grinding and polishing are performed using handheld angle grinders

average sampling time Bartoli et al., 2012

>0.1

≤0.1

≤0.05

≤0.025

RCS exposure in factories for the production of kitchen countertops using artificial stone

Measurement in a finishing factory where 60 workers were employed

Candido and Compagnoni, 2013

2. Survey conducted by the INAIL (Italian Workers’ Compensation Authority) Marche Regional Office

Both natural and artificial stones were used (products: paving blocks for building and kitchen countertops)

average sampling time

RCS exposure in factories for the production of kitchen countertops using artificial stone

Quartz A.S.= 1% Granite=4% Other stones=95%

Quartz A.S.= 15-55% Granite=10-35%

Other stones=10-75%

Quartz A.S.= 15-55% Granite=10-35%

Other stones=10-75%

Quartz A.S.= 1% Granite=4% Other stones=95%

Dressing using an angle grinder (dry process) on a dust purification bench Crystalline Silica Exposure : 0.076 mg/m3

QUARTZ artificial stone

photo by Compagnoni

RCS exposure in factories for the production of kitchen countertops using artificial stone

RCS exposure in factories for the production of kitchen countertops using artificial stone

Scratching using an angle grinder (dry process)

Dust purification bench with water depuration

www.centroventilazione.com

RCS exposure in factories for the production of kitchen countertops using artificial stone

www.centroventilazione.com

Scratching using an angle grinder (dry process)

Dust purification wall with water depuration

Dressing using an angle grinder (dry process) Crystalline Silica Exposure : 0.012 mg/m3

NATURAL MARBLE stone

photo by Compagnoni

RCS exposure in factories for the production of kitchen countertops using artificial stone

2 suspected cases of silicosis were found in a factory where quartz artificial stone slabs were processed to produce kitchen countertops

Azzone et al., 2014

Cutting , grinding and polishing operations were often performed through dry processes, in a dusty workplace, without proper general and local exhaust ventilation systems

3. Monitoring conducted by the ASL (Local Health Authority) of Asti and ARPA (Regional Agency for the Protection of the Environment) of Piedmont

photo by Azzone, Bisio and Scibelli

RCS exposure in factories for the production of kitchen countertops using artificial stone

Activity Factory

Concentration (mg/m3)

(%)

Respir. Dust

Respir. Quartz

Respir. Quartz

Slab cutting (handheld angle grinder - dry) A 5.2 4.900 94%

Slab cutting (milling machine - wet)

A

0.5 0.430 86%

Edge polishing (Band polishing machine - wet) 1.0 0.940 94%

Pantograph engraving (wet) 0.4 0.400 100%

Surface polishing (polishing machine – wet) 0.4 0.320 80%

average sampling time

Azzone et al., 2014

>0.1

≤0.1

≤0.05

≤0.025

Respirable dust and silica exposure

photo by Azzone, Bisio and Scibelli

A new monitoring was carried out in the facory after a radical redesign and reorganization of the facility

Azzone et al., 2014

Survey conducted by the ASL (Local Health Authority) of Asti and ARPA (Regional Agency for the Protection of the Environment) of Piedmont

Sawing Polishing Dressing edges

RCS exposure in factories for the production of kitchen countertops using artificial stone

PPE: mask FFP3 Personal Protective Equipment

Activity Factory

Concentration (mg/m3)

(%)

Respir. Dust

Respir. Quartz

Respir. Quartz

Slab cutting (handheld angle grinder - dry) A 5.2 4.900 94%

Slab cutting (milling machine - wet)

A

0.5 0.430 86%

Edge polishing (Band polishing machine - wet) 1.0 0.940 94%

Pantograph engraving (wet) 0.4 0.400 100%

Surface polishing (polishing machine – wet) 0.4 0.320 80%

Azzone et al., 2014

Activity Factory

Concentration (mg/m3)

(%)

Respir. Dust

Respir. Quartz

Respir. Quartz

Slab cutting (handheld angle grinder - dry) A BEFORE 5.2 4.900 94%

Slab cutting (milling machine - wet)

A BEFORE

0.5 0.430 86%

Edge polishing (Band polishing machine - wet) 1.0 0.940 94%

Pantograph engraving (wet) 0.4 0.400 100%

Surface polishing (polishing machine – wet) 0.4 0.320 80%

Slab cutting (new milling machine - wet)

A AFTER

0.2 0.017 9%

Edge polishing (new polishing machine - wet) 0.2 0.013 7%

Slab cutting (new milling machine - wet) 0.1 0.014 14%

Slab cutting (new milling machine - wet) 0.2 0.018 9%

Dressing and polishing (handheld grinder- wet) 0.1 0.013 13%

Dressing and polishing (handheld grinder- wet) 0.1 0.017 17%

Slab cutting (new milling machine - wet) 0.1 0.006 6%

>0.1

≤0.1

≤0.05

≤0.025

Respirable dust and silica exposure average sampling time

RCS exposure - Efficacy of engineering controls under controlled conditions

Cooper J.H., Johnson D.L. and Phillips M.L. (2014) Respirable Silica Dust Suppression During Artificial Stone Countertop Cutting. Ann. Occup. Hyg., 1–5

Wetted blade: common water stream attachment to suppress the dust Water curtain: fan-shaped, secondary water flow, sprayed normal to the path of the ejected stone dust Local Exhaust Ventilation (LEV): cowl mounted to the guard surrounding blade

Test Wetted

blade + LEV

Wetted blade + water curtain

Wetted blade only

Dry

1 n.d. 2.944 4.846

44.37 2 0.139 0.920 2.563

3 0.201 3.405 1.874

4 0.669 1.373 2.209

Respirable quartz dust concentrations (mg/m3)

Handheld circular saw cutting

0

Conclusions

Quartz artificial stone contain very high percentage of crystalline silica. In the absence of effective dust controls, the cutting, grinding and polishing quartz artificial stone generate very dangerous levels of exposure to silica. Nonetheless, the implementation of effective dust controls, including machines equipped with efficient dust suppression systems, local exhaust ventilation systems, PPE, and administrative controls, air monitoring, and worker training can adequately control the risk.

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ludovica.malaguti@iss.it m.mecchia@inail.it

Thank you for your attention!