Toothbrushes are among those products that contain PVC plastics and are used several times a day by people all around the world. Therefore, if toothbrushes contain a significant amount of phthalate, they could be very dangerous and harmful.
Phthalates are chemicals found in everyday products and PVC plastics, mainly because of their ability to enhance flexibility and durability. Phthalates could have many negative effects on individuals based on their daily exposure to these materials.
A majority of previous studies have focused on the determination of phthalates in plastic bottled water, plastic toys, and cosmetics. However, negligible amounts of scientific experiments have been done on phthalates of toothbrushes so far.
This experiment was done to determine the phthalate concentration of Colgate, Equate, and Reach toothbrushes. The method was Gas Chromatography/Mass Spectrometry. The results obtained showed a significant amount of phthalates in the Colgate brand toothbrushes with an average of 1.15 DEHP ppm. The phthalate present in Reach adult’s toothbrush was found to be Dibuthyl, DBP. Also, for the Equate kid’s power toothbrush no phthalate was found.
This experiment was a continuation of the same project started in 2013, but the previous study had a few limitations that were corrected while conducting this present research.
At first, this experiment was done with the standard solutions that had the phthalate concentration of 0.5 ppm to 50 ppm. This 0.5 ppm to 50 ppm interval of phthalate concentration resulted in a calibration curve that was not a best representation of the data. The 50 ppm standard solution made the slope and y intercept of the trend line incorrectly larger, all of which resulted in a negative phthalate concentration of the Equate kid’s toothbrush sample in hexane. Therefore, after statistical calculations it was concluded that 50 ppm standard solution was an outlier that needed to be removed.
The current results presented in this paper are based on the smaller interval of phthalate concentration, 0.5 ppm to 10 ppm. Also, to improve the calibration curve the number of standard solutions were increased to conduct the present research while continuing the same procedures. The accuracy of the calibration curve graph is improved by increasing the number of standard solutions and as a result more accurate equation of a trend line is obtained. In this manner, the precision and accuracy of DEHP concentration reported for a specific brand was significantly improved.
Another limitation of the previous study was the small number of samples taken from each brand. In this experiment, 12 samples were taken at random from the three brands of Colgate, Equate kid’s, and Reach adult’s toothbrush. It is critical to take at least four samples from that brand and find the average phthalate concentration present in all toothbrushes tested from that specific brand.
Further research needs to be conducted regarding the same issue with the goal of producing additional results and trying to improve the limitations of this study. In general, phthalate should be removed from the products that people use in their everyday life based on its harmful effects on human health. In return, other plasticizers should be replaced to maintain not only the flexibility and durability of products, but also to incur fewer health risks for humans and the environment.