Tank-washing gave rise to a huge number of small spills, and tanker accidents such as those involving the Torrey Canyon, Exxon Valdez, Metula, and St. Peter resulted in huge, concentrated spills. Blowouts were not infrequent, but most occurred on land or in shallow water, and most could be stopped relatively easily.
油轮曾经是造成大部分原油泄漏的罪魁祸首。油仓清洗引发了数量庞大的小规模泄漏事件，而诸如托利峡谷号、埃克森·瓦尔德斯号和圣彼得堡号等油轮事故则导致了大规模集中的原油泄漏。井喷事故也屡见不鲜，但绝大多数都发生在陆地或浅水区域，可以比较容易地加以遏制。