The Institute of Practitioners in Advertising (IPA) has issued an open letter to Google and Facebook calling for an improvement to standards of brand safety, measurement and viewability in their online video advertising.

The body, which represents UK ad agencies, has accused the two companies of not acting fast enough to resolve the issues.

The IPA’s director general, Paul Bainsfair, believes that as the biggest online video suppliers, Google’s YouTube and Facebook “have a responsibility” to maintain advertising standards.

“Whilst we acknowledge that small steps towards addressing recent concerns have been taken, our advertisers and agencies are increasingly telling us that this progress is neither fast, nor significant, enough,” he said, “We believe it is incumbent upon the key players in this sector, therefore, to show real commitment to finding solutions to these problems.”

In a response to the letter, Facebook’s spokesperson commented the company is serious about taking its “commitment to advertisers”.

“In the last few months we’ve announced an extra 3,000 content reviewers to nearly double our existing team, as well as new buying options and controls for advertisers that give choice and transparency over how and where ads appear on the platform,” the spokesperson explained, adding Facebook has also updated its metrics.

Zenith’s Online Video Forecasts 2017 report revealed that users will spend approximately 47.4 minutes a day viewing online videos this year, an increase from 39.6 minutes in 2016, which is driven by platforms such as YouTube and Facebook. As advertising continues to grow, so do concerns over safety and standards.

Bainsfair’s letter follows recent issues around extremist content on YouTube and Facebook’s measurement errors and marks yet another attempt at improving standards in advertising. In June, the IPA and the Incorporated Society of British Advertisers (ISBA) published “A Matter of Fact”, a paper calling the industry to provide accountable media audience data.