Insect repellents dimethyl phthalate

It has its limitations, but is still in use today in so-called natural insect repellents. But its disadvantages inspired researchers to search for more effective alternative compounds. Many of the early attempts at creating synthetic insect repellents were initiated by the US military. Out of this research came the discovery of the repellent dimethyl phthalate in 1929. This material showed a reasonable level of effectiveness against certain insect species, but it was ineffective against others. Two other materials were developed as insect repellents Indalone was found to repel insects in 1937, and Rutgers 612 (2-ethyl-l,3-hexane diol) was synthesized soon after. Like dimethyl phthalate, these materials had certain limitations which prevented their widespread use. 

Dibutyl phthalate is used in pharmaceutical formulations as a plasticizer in film-coatings. It is also used extensively as a solvent particularly in cosmetic formulations such as anti-perspirants, hair shampoos and hair sprays. In addition to a number of industrial applications, dibutyl phthalate is used as an insect repellent, although it is not as effective as dimethyl phthalate. 

In pharmaceutical applications, dimethyl phthalate is used in film-coating and as a topically applied insect repellent. Acute exposure to the eyes and mucous membranes can cause irritation although dimethyl phthalate is considered less irritant than diethyl phthalate. Inhalation of dimethyl phthalate can cause irritation of the respiratory tract oral ingestion can cause a burning sensation in the mouth, vomiting, and diarrhea. Owing to the low water solubility and relatively high lipid solubility, dimethyl phthalate may accumulate in body tissues after chronic exposure, which may cause central nervous system depression. 

Insect repellants. The medical welfare of human beings is safeguarded by insect repellants, such as dimethyl phthalate and wi-diethyltoluamide against mosquitos, and dibutyl phthalate against the mites that carry scrub typhus (see Christophers, 1947 for the physical principles involved). 

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