Expanded Perlite Horticultural Media

Perlite is the generic name for a naturally occurring siliceous volcanic rock. We are manufacturing the filter perlite in one of our special kilns at temperatures of more than 1100o C, whereby the original raw material is expanding up to 20 times its original volume, and we achieve a new product : a white, sterile granular.



Expanded perlite1

Production Furnace for Expanded Perlite




Chemical Composition:


SiO2        :  71-74%

AL2O3     :  13-14.5%

TiO2        :  0.06%

Fe2O3      :  0.6-0.8%

CaO          :  0.2-0.4%

MgO         :  0.1-0.2%

Na2O3      :  3-4%     

K2O          :  8.6-9%



Organic substances        none

Inert Material     Max 1.0 ml/50gr.


Wet ability Easy dispersion in water


Pb Soluble          max. 1.0 ppm


As soluble         max. 0.05 ppm


Floaters test     max. 32ml/20 grams


Hygroscopicity                  none


Organic Substances:         none



Physical properties   of   Perlite:


Colour:                                       Very Light-White Powder

Free Moisture, max.                 0,5% : 0 when leaving factory

pH (of water slurry):                6 – 8 suspension 10%)

Specific Gravity:                       2200 – 2400 kg/m3

Bulk Density:                            40 – 170 kg/m3

As filter aid & filler                    7 – 50µ + 0,1 – 6,0 mm

Softening temperature:           1100°C

Melting point:                            1350°C

Oil Absorption (Astm D281)   120 – 200



Solubility…Soluble in hot concentrated alkali and HF, moderately soluble (<10%) in 1N Na0H. Slightly soluble in (<3%) in mineral acids (1N). Very slightly soluble (<1%) in water or weak acids

Wet ability: Easy dispersion in water and non water liquids








  1. Scantox, Lab. No. 10018, 20/10 81, test referring to poisonous material.


  1. Rosner-Hixon Lab. Chicago 16/6 77, test referring to poisonous material.


  1. Fisons Ltd. England, 1979 test referring to crystalline Quarts .


  1. Technology and Materials California, 5/6 79, test referring to crystalline Quarts


  1. Equitable Environmental Health, Inc. California, Lung function with Perlite workers


  1. Svensk Arbejdstilsyn 20/2 78. Test referring to crystalline Quarts in Perlite und Kiselgur.


  1. Jysk Teknologisk Institut 24/9 82. Test regarding burning properties of Perlite .


  1. „Heath insulation control“ is regularly tested by the Technological Institute of Denmark


  1. Journal of Occupational Medicine/Volume 28, no. 3/March 1986. Test of the Lung function of Perlite workers.


  1. „Industrial Employees Council“. Summary Report on Perlite Worker Survey, Tulane University, April 1990.


  1. 1994, Perlite Worker Health Study, Tulane University, New Orleans, January 1995.


  1. Danish National Labour Inspection. 1989. Report on Crystalline Quartz


  1. Ergo Forschungsgesellschaft m.b.H. Hamburg. Dioxin Test re. Animal & Human Being Feed


  1. Arbejdsmiljøtilsynet & By & Byg, 2002 Report on Crystalline Quartz


  1. DIOXIN & PCB’s. Figures tested are significantly below current and proposed limits according to the EU Directive 2002/32/EU. Report from August, 2003.



Created and Hosted by WYSIWYG Computers