This follows a wave of concern over inappropriate content which has left Google scrabbling to convince advertisers that it has a handle on the issue.
Going a step further Google will now cast an eye over all content within its elite Google Preferred channels which command premium prices amongst advertisers.
An Alphabet spokeswoman said: "We built Google Preferred to help our customers easily reach YouTube’s most passionate audiences and we’ve seen strong traction in the last year with a record number of brands. As we said recently, we are discussing and seeking feedback from our brand partners on ways to offer them even more assurances for what they buy in the Upfronts."
Advertisers have expressed discomfort at the free-for-all nature of YouTube which has resulted in a number of scandals breaking over inappropriate content – most recently an incident in which YouTube star Logan Paul broadcast footage of a suicide victim.
Nevertheless Google has a gargantuan challenge on its hands to make good on its promises with some 10,000 moderators working alongside artificial intelligence software to root out content unsuited to advertising.