Final answer:
An intentional and knowing violation or a violation committed with plain indifference to the law is considered a serious violation by OSHA.
Step-by-step explanation:
An intentional and knowing violation that an employer commits, or a violation that is committed with plain indifference to the law is considered a serious violation by OSHA. For this type of violation, OSHA may propose penalties of up to $125,000 for each violation.