The diesters of 1,2-benzenedicarboxylic acid are frequently introduced as phthalic acid esters (PAEs) or phthalates. Toxic PAEs present in the environment are dimethyl phthalate (DMP), diethyl phthalate (DEP), di-isobutyl phthalate (DIBP), dibutyl phthalate (DnBP), butyl benzyl phthalate (BBP), and di-(2-ethylhexyl) phthalate (DEHP). Ortho, meta, and para are the isomeric forms of phthalic acid based on the orientation of the carboxylic acid with one another. However, the ortho form of benzene dicarboxylic acid, which is developed when a particular alcohol reacts with phthalic acid to form the desired ester, is used mostly as the plasticizer and brings about the significant contribution of all phthalate esters manufactured globally. They are widely utilized for manufacturing plastic products, polyvinyl chloride and other polymers to increase longevity and flexibility (Gao & Wen 2016;Yang et al. 2018). Nearly 60 discrete phthalate esters and its by-products are used for numerous products, i.e., cosmetics, adhesives, elasticity, lubricants, plastic manufacturing, packaging material, insecticides, and additives in paints to increase the longevity and flexibility of the plastic product (Eichler et al. 2019). A list of toxic phthalates with its molecular weight, chemical structure, toxic effects, and applications in the industrial sector are mentioned in Table 1.
Molecular weight, chemical structure, and application of some toxic phthalates
| Phthalate esters | Mol. weight and CAS | Chemical structure | Solubility in water (mg L−1) | Toxic effects | Applications |
|---|---|---|---|---|---|
| Dimethyl phthalate (DMP) | 194.2 and 131-11-3 |  | 2,014 | Liver problems, reproductive difficulties | Air freshener, shampoo, insecticides, etc. |
| Diethyl phthalate (DEP) | 222.2 and 84-66-2 |  | 287 | Male reproductive issues, liver problems | Plasticizers, aerosol sprays, cosmetics fragrances, nail polish, etc. |
| Dibutyl phthalate (DnBP) | 278.3 and 84-74-2 |  | 2.35 | Teratogenic, testicular damage, carcinogenic | Cosmetics, anti-foaming agents, printing inks, wrapping materials. |
| Di-(2-ethylhexyl) phthalate (DEHP) | 390.6 and 117-81-7 |  | 0.00 | EDCs, Cytotoxicity; liver problems; elevated cancer risk. | Medical tubes, blood storage bags, gloves, furniture, diapers, children's dolls, packaging films, dialysis bags, and air tubes. |
| Butyl benzyl phthalate (BBP) | 312.36 and 85-68-7 |  | 0.950 | Cellular toxicity | Vinyl flooring, wrapping materials, carpet tiles, conveyor belts, automotive, adhesives, artificial leather. |
| Phthalate esters | Mol. weight and CAS | Chemical structure | Solubility in water (mg L−1) | Toxic effects | Applications |
|---|---|---|---|---|---|
| Dimethyl phthalate (DMP) | 194.2 and 131-11-3 | | 2,014 | Liver problems, reproductive difficulties | Air freshener, shampoo, insecticides, etc. |
| Diethyl phthalate (DEP) | 222.2 and 84-66-2 | | 287 | Male reproductive issues, liver problems | Plasticizers, aerosol sprays, cosmetics fragrances, nail polish, etc. |
| Dibutyl phthalate (DnBP) | 278.3 and 84-74-2 | | 2.35 | Teratogenic, testicular damage, carcinogenic | Cosmetics, anti-foaming agents, printing inks, wrapping materials. |
| Di-(2-ethylhexyl) phthalate (DEHP) | 390.6 and 117-81-7 | | 0.00 | EDCs, Cytotoxicity; liver problems; elevated cancer risk. | Medical tubes, blood storage bags, gloves, furniture, diapers, children's dolls, packaging films, dialysis bags, and air tubes. |
| Butyl benzyl phthalate (BBP) | 312.36 and 85-68-7 | | 0.950 | Cellular toxicity | Vinyl flooring, wrapping materials, carpet tiles, conveyor belts, automotive, adhesives, artificial leather. |
Mankidy et al. (2013); Zhang et al. (2015); Giuliani et al. (2020); Das et al. (2021).