Section 5 of the Act contains the "general duty clause." The "general duty clause" requires employers to 1) Maintain conditions or adopt practices reasonably necessary and appropriate to protect workers on the job; 2) Be familiar with and comply with standards applicable to their establishments; and 3) Ensure that employees have and use personal protective equipment when required for safety and health. OSHA has established regulations for when it may act under the "general duty clause." The four criteria are 1) There must be a hazard; 2) The hazard must be a recognized hazard (e.g., the employer knew or should have known about the hazard, the hazard is obvious, or the hazard is a recognized one within the industry); 3) The hazard could cause or is likely to cause serious harm or death; and 4) The hazard must be correctable (OSHA recognizes not all hazards are correctable).