Effective encouragement of enterprises in the direction of environmental protection, reduction of the negative impact of production on the environment, increase of investment attractiveness and environmental image is possible provided that the methodology for assessing the overall level of environmental safety of the enterprise is developed and practically tested. In the article, the formula for calculating the integral indicator of the overall level of the enterprise's environmental safety is developed; it is based on three partial integral coefficients: an integral coefficient of environmental damage; an integral coefficient of the impact of economic factors; an integral coefficient of the impact of environmental and economic factors. The use of correlation and regression analysis has confirmed the validity of the developed economic and mathematical model, the existence of interconnections between its indicators.