The article provides the results of studying the effect of 0.1, 1.0, 2.5, 5.0, 7.5, and 10% aqueous suspensions of bottom ash and technical carbon on the germination vigor of the seeds of oil flax and the environmental safety of its use in terms of the content of heavy metals. Laboratory experiments were performed at the environment lab, field experiments – at the experimental field of the Kokshetau State University n.a. S. Ualikhanov. The laboratory germination vigor of the seeds, the length of seedlings, and the mesocotyl were determined according to the Interstate Standard Agricultural Seeds GOST 12038–844. In the field experiment on studying dosages of introducing the drug, the content of heavy metals was determined by the method of stripping voltammetry. The preparation is a mixture of bottom ash and technical carbon in the ratio of 2:1. It has been found that the use of a 5% aqueous suspension of the preparations contributes to increasing the laboratory germination to 97.0% (88% in the reference), the length of the mesocotyl to 80 mm (55 mm in the reference), the length of roots to 79 mm, and the weight of germinated seeds to 1.6 grams (in the reference, these values were 46 mm and 0.6 g, respectively). After the introduction of the preparation made of bottom ash and technical carbon at the dosages of 100, 200, 300, 400, and 500 kg/ha, the content of heavy metals insignificantly increases, compared to the reference, but does not exceed the permissible levels in the soil, in the stalks, and in the grains of oil flax; that is, the introduction of the preparation into the soil at the dosages of 100 – 500 kg/ha is ecologically safe. The experimental data have shown that the maximum effect is ensured by pre-sowing treatment of oil flax seeds with a 5% solution of aqueous suspension made of bottom ash and technical carbon, where the laboratory germination capacity of the seeds increased by 10.2%.