Abstract title  Building materials: analysis of the efficiency of the ammonium quaternary to control Sick Building Syndrome
Internet ID      1437
Objectives:
Three specimens of four different types of bricks, totaling 12 bricks, were the objects of analysis of the present research: calcium silicate bricks, clay bricks, ecological brinks and concrete bricks. The bricks were immersed for 30 minutes in freshly prepared 2% ammonium quaternary (SHINE®) solution thereby guaranteeing the infiltration of the product. All the bricks were weighed before and after immersion in order to analyze differences in weight. Commercial mortar® was prepared according to the instructions of the manufacturer, with and without the use of 2% SHINE disinfectant. Matte white acrylic paint (RomaÒ) was also used in the tests with disinfectant being incorporated in half of the paint and the other half being used according to the original formulation. The surface of all the bricks were inoculated using an automatic pipette with 30 mL Aspergillus fumigatus fungus inoculum prepared using the McFarland scale. The specimens were placed in plastic boxes and incubated in an oven at 30°C with records of the humidity and environmental temperature made daily. Colony forming units (CFU) were counted and phenotypic variation of fungal growth was investigated

Methods:
Three specimens of four different types of bricks, totaling 12 bricks, were the objects of analysis of the present research: calcium silicate bricks, clay bricks, ecological brinks and concrete bricks. The bricks were immersed for 30 minutes in freshly prepared 2% ammonium quaternary (SHINE®) solution thereby guaranteeing the infiltration of the product. All the bricks were weighed before and after immersion in order to analyze differences in weight. Commercial mortar® was prepared according to the instructions of the manufacturer, with and without the use of 2% SHINE disinfectant. Matte white acrylic paint (RomaÒ) was also used in the tests with disinfectant being incorporated in half of the paint and the other half being used according to the original formulation. The surface of all the bricks were inoculated using an automatic pipette with 30 mL Aspergillus fumigatus fungus inoculum prepared using the McFarland scale. The specimens were placed in plastic boxes and incubated in an oven at 30°C with records of the humidity and environmental temperature made daily. Colony forming units (CFU) were counted and phenotypic variation of fungal growth was investigated

Results:
The number of fungal colonies on the bricks, mortar and paint treated with 2% SHINE disinfectant alone was lower or even eradicated compared to the control group. On comparing the different types of bricks treated with the disinfectant, ecological bricks were the best and concrete bricks were the worse in terms of inhibition of fungal growth.

Conclusion:

The inhibitory activity observed in this research is important because Aspergillus fumigatus is often resistant to different chemical compounds. Future research with this disinfectant should investigate new research proposals, with adaptations and standardizations in respect to time, concentration and the stability of the product.