Traditional automatic control systems do not solve the task of limiting the harmful effects of technical objects on the environment. The problem is to increase the effectiveness of means of its protection against the harmful effects of industry. Relevant is the use of indicators of environmental performance of technical objects as controlled parameters. A new approach to the control of technical objects is proposed. As the main control parameter it proposed to adopt the level of their ecological efficiency. Complicating circumstances of solving the problem is the insufficient knowledge of the factors of harmful effects on objects of living nature, their intensity, interrelation, mechanism, strength, and dynamics of exposure. Improving the economic efficiency of technical objects leads to an increase in their ecological efficiency. The solution to the problem is facilitated by the fact that traditional ACS should be left in action, adding to them an ecological efficiency control component. Heat-powerengineering has a large impact on the environment through emissions and discharges of harmful substances and heat. To give to ASC the functions of controlling the ecological efficiency of the boiler (for SOy emission), it is necessary to apply an additional, new control loop - regulator of SOy concentration in furnace gases. An urgent task in the use of direct control of the ecological efficiency of boiler-furnace systems is the development and production of physical quantity sensors, reflecting the level of aggressiveness of the source of hazard, working in real time. Direct control of indicators of ecological efficiency is much easier in other branches of industry, in particular, in its food branch, where objects do not have a large-scale complex negative impact on the environment.