Socially responsible investing helps investors differentiate between companies that contribute to the well-being of people as well as the planet and companies that have lower standards in the areas of the environment, human rights and other criteria. This is because socially responsible investment (SRI) funds have "screens" applied to them. Screens can be positive (ethical business practices, safe workplaces, good environmental performance) or they can be negative (involvement in weapons, gambling, tobacco, alcohol). Each fund applies its own blend of screens. About 80% of SRI funds include environmental screens.