This is the 18359th most frequent Russian word.
экологичных
Environmentally friendly.
The word 'экологичных' is used here as an adjective modifying 'materials', indicating that the materials chosen are environmentally friendly.
Мы выбрали экологичных материалов для ремонта дома.
We chose eco-friendly materials for renovating the house.
Here, 'экологичных' modifies 'technologies', highlighting the nature of production methods being not harmful to the environment.
При производстве использовались экологичных технологий.
Environmentally friendly technologies were used in the production.
In this sentence, 'экологичных' refers to 'solutions', signifying measures or systems that are environmentally considerate.