Sen. Richard Blumenthal, D-Conn., the subcommittee’s chair, said at the opening of Tuesday's hearing that Facebook is facing its "Big Tobacco moment -- a moment of reckoning," and that it's time to hold big tech accountable.

"Facebook knows its products can be addictive and toxic to children. And it's not just that they made money, again, it's that they value their profit more than the pain that they cause the children and their families," Blumenthal said, while whistleblower Frances Haugen nodded along.

“Facebook exploited teens using powerful how algorithms and amplified their insecurities,” Blumenthal said, adding he hopes Haugen can address the question as to whether there is such a thing as a safe algorithm for the social media giant.

Blumenthal, whom Haugen has allegedly showed leaked Facebook documents to, said the company’s “profit was more important than the pain that they caused" and called on CEO Mark Zuckerberg to come before the committee.

“Mark Zuckerberg ought to be looking at himself in the mirror today, and yet, rather than taking responsibility and showing leadership, Mr. Zuckerberg is going sailing," Blumenthal said, in an apparent reference to the billionaire's recent social media posts.

"Facebook appears to have misled the public and investors, and if that's correct, it out to face real penalties as a result of that and misleading and deceptive representation," he said.

Facebook CEO Mark Zuckerberg has still not publicly commented on whistleblower France Haugen’s claims that the company manipulated its algorithm to incentivize disinformation, hatred and polarization among its users.

Zuckerberg did, however, weigh in on Monday evening following the platform’s six-hour outage, apologizing for the disruption.

Nick Clegg, Facebook's vice president of global affairs, has responded to Haugen's claims on behalf of the company while Zuckerberg stays silent and said in a CNN interview on Sunday those making accusations that the company is commissioning research to "deliberately" brush it aside have it "back to front."

"If we didn't want to address those questions, we wouldn't commission the research in the first place," Clegg said.

Also among Haugen’s accusations is that Facebook relaxed safeguards surrounding the 2020 election content after Nov. 3, allowing misinformation to spread and fuel the Jan. 6 attack on the Capitol.

Clegg told CNN that blame "lies squarely with the people who inflicted the violence and those who encouraged them, including President Trump."

Sen. Richard Blumenthal, D-Conn., who chairs the Senate Commerce Subcommittee on Consumer Protection, Product Safety and Data Security, promised "riveting" testimony that would prove to be a "breakthrough moment" ahead of Tuesday's hearing.

"This whistleblower is one gutsy, smart, strong woman who is speaking truth to the nation about how Facebook is dragging children into dark places and deepening their insecurities with online bullying, self-injuries, suicide, eating disorders, and I think she will tell us what it's like to see the top Facebook executives make decisions that profit Facebook at the expense of children's safety, how they put children’s safety above -- below profit-making motive," Blumenthal told reporters Monday evening.

Blumenthal said the documents Haugen has provided show a "searing indictment of the top corporate management of Facebook ignoring their own study, their own surveys and research that showed how they were putting kids in danger, just so they could profit more."

He also alleged Facebook has been "utterly unresponsive" to the committee's requests to disclose their own studies and said he hopes Haugen coming forward will encourage other whistleblowers.

Frances Haugen, a former Facebook data scientist turned whistleblower, is scheduled to testify before the Senate Consumer Protection Subcommittee at 10 a.m. on Facebook and Instagram’s impacts on young users in a hearing entitled, "Protecting Kids Online: Testimony from a Facebook Whistleblower. "

Beyond alleging Facebook’s knowledge of its platforms’ negative impact on teenagers and young girls, Haugen has reportedly come forward with documents showing the social media giant has also ignored but is aware of how hate speech and misinformation are emphasized on their sites.

Haugen, who revealed her identity during a Sunday interview on CBS' "60 Minutes" has been cooperating with the offices of Sen. Richard Blumenthal, D-Conn., and Sen. Marsha Blackburn, R-Tenn., chair and ranking member of the Senate committee that is assessing potential regulations for the social media giant.

Facebook director of policy communications Lena Pietsch released a statement following whistleblower Frances Haugen's testimony, attempting to discredit her knowledge of the company.

"Today, a Senate Commerce subcommittee held a hearing with a former product manager at Facebook who worked for the company for less than two years, had no direct reports, never attended a decision-point meeting with C-level executives – and testified more than six times to not working on the subject matter in question. We don’t agree with her characterization of the many issues she testified about," Pietsch wrote.

"Despite all this, we agree on one thing; it’s time to begin to create standard rules for the internet. It’s been 25 years since the rules for the internet have been updated, and instead of expecting the industry to make societal decisions that belong to legislators, it is time for Congress to act," the statement finished.

Multiple times during the hearing, lawmakers invited Facebook CEO Mark Zuckerberg and communications spokespersons to appear before Congress and testify themselves.

Zuckerberg has remained silent on Haugen's allegations for days, and multiple senators mocked the billionaire over recent social media posts of him out sailing instead.

-ABC News' Zunaira Zaki