Is set off a chain reaction formal or informal?

It is neutral, but it often appears in written English and news reports.

How is it different from cause?

Cause is general. Set off a chain reaction means one event leads to many connected events.

Can I use it in academic writing?

Yes, especially when describing connected effects in science, economics, or social topics.

← Dictionary

set-off-a-chain-reaction

/ˌset ɒf ə ˌtʃeɪn riˈæk.ʃən/

IELTSAcademic

verb

to cause a series of events or reactions that spread from one thing to another. One action starts many later actions.

The news set off a chain reaction.
One mistake can set off a chain reaction.
His comment set off a chain reaction of complaints.

Adinary Nuance

Set off a chain reaction is stronger than simply cause or start. It suggests one event triggers many connected events, often quickly and not always in a planned way. Writers use it when they want to show spreading effects, not just a single result.

In other languages

Vietnamese: gây ra phản ứng dây chuyền
Spanish: provocar una reacción en cadena
Chinese: 引发连锁反应
Japanese: 連鎖反応を引き起こす
Korean: 연쇄 반응을 일으키다

Etymology

This phrase uses the old phrasal verb set off, meaning “start” or “cause,” plus chain reaction. Chain reaction became common in science in the 1900s, then spread into general English.

Common phrases

set off a chain reactionset off a chain reaction of eventsset off a chain reaction in the market

Synonyms

trigger spark cause start

Frequently asked questions

Is set off a chain reaction formal or informal?: It is neutral, but it often appears in written English and news reports.
How is it different from cause?: Cause is general. Set off a chain reaction means one event leads to many connected events.
Can I use it in academic writing?: Yes, especially when describing connected effects in science, economics, or social topics.