Toxicological substantiation for didecyldimethylammonium chloride occupational exposure standard
Authors: Zhminko P.G. , Voronina V.M. , Svitlyi S.S. , Rudaya L.O. 
Published: July 2020

Dydetsyldymetylammonium chloride (DDAC) is used as a raw material in the chemical industry for the production of some insecticidal, fungicidal and aldehydic preparations and disinfectants in which it is an active ingredient.

Aim of the Research. To establish a scientific substantiation for DDAC indicative safe exposure level (ISEL) in the workplace air by analyzing and summarizing the bibliographic data about the degree of DDAC danger.

Methods. To establish a scientific substantiation for DDAC occupational exposure standard the following properties were analyzed: its physical and chemical characteristics; LD50 (lethal dose) for oral and dermal exposure; LC50 (lethal concentration) for inhalation exposure; irritant and sensitizing properties; NOAELs (no-observed adverse effect level) for DDAC were determined in sub-acute and subchronic experiments under different conditions of exposure as well as its long-term effects.

The calculation of DDAC ISEL in the workplace air was performed using equations which make allowance for the toxicity properties of the preparation when it is administered to laboratory animals through different routes.

Results. DDAC is an imported product used as an active ingredient in the production of certain pesticides and disinfectants.

DDAC falls into the category of non-volatile substances: its vapor pressure is <1x10-2 Pa at 20° C, at 50оC – 2,3x10-4 Pa (US ISC)

When introduced into the gastrointestinal tract, the substance is classified as moderately dangerous – Category 3 (in accordance with Globally Harmonized System of Classification and Labeling of Chemicals / GHS / United Nations, New York and Geneva, 2017) and has a mild skin-resorptive effect (Category 4, GHS). Its adverse local impact on the skin has been identified. The substance LC50 after inhalation exposure is 70 mg/m3 (Category 2, GHS). DDAC produces marked irritant action on the skin and conjunctiva of rabbits (Category1B, GHS). Erythema, crust and swelling were recorded on skin. Burns, corrosion, acute keratoconjunctivitis were observed when the substance got onto conjunctiva. No sensitizing effect of the preparation was found (not classified, GHS). The cumulative properties of the substance are incomplete. NOAELs were determined in sub-acute and sub-chronic experiments after oral, dermal and inhalation exposure. The most affected organs and systems are skin, eyes, gastrointestinal tract, liver. Mutagenic, carcinogenic, embryotoxic, teratogenic and toxic effects on the reproductive function are not limiting harmful criteria.

Calculation of the value of DDAC ISEL in the workplace air was conducted by the equations of regressive dependence, which take into consideration the parameters of acute toxicity. Making allowance for the degree of its hazard and the risk of developing the pathology of general genesis under the effect of the substance, the recommended ISEL value in the workplace air is 0.2 mg/m3, aggregate state “a” with the mark “protection of eyes and skin is necessary”.

Key Words: dydetsyldymetylammonium chloride, DDAC, ISEL in the workplace air, insecticides, disinfectants.