Microplastics are so widely dispersed and abundant throughout the globe that many scientists consider them to be important markers of the recent and current time, which is known as The Plasticene. The effects of microplastics are still not fully known, though. Because microplastics are multiple stressors with a variety of physical-chemical characteristics, understanding their impact is quite complicated. If toxic chemicals are transported by microplastics in ecosystems, acting as vectors of transport. Also, many dangerous chemicals are added during polymer production to enhance their properties and lengthen their life and these chemicals must have detrimental effect. To date, many significant studies have done, making a good progress to understand the effect of the key plastic additives on the environment. At the end of the day, these additives are thrown into our environment and, hence become a source of many health issues, especially, when are coupled with micro-plastics. The current study will review thoroughly the most toxic and dangerous chemicals used in the plastic industry, elaborating the effects on organism health. Also, it provides information about the works that explored their abundance on microplastics.