Zero-waste products like these are supposed to reduce trash.

We've saved literally millions of packages from landfill, and that's really important to me.

But there are still billions of bottles that end up in landfills and on beaches every year.

So, can recipes like this really help cut worldwide waste?

We went to factories in Vancouver and Tasmania to find out.

At Beauty and the Bees in Tasmania, a mix of oils and melted beeswax are the first ingredients in a shampoo bar.

We've never used any plastic packaging, ever; we use only paper, tin, glass, or wood.

Jill Saunders started Beauty and the Bees 30 years ago.

Her products use only natural ingredients.

It's entirely chemical-free, and the suds are biodegradable⏤that's very important, too.

Clay from the Atlas Mountains in Morocco blended with castor oil makes the shampoo thick and foamy.

So, he [is] gonna pour.

Workers add Tasmanian leatherwood honey and lye.

Lye is an ancient ingredient that turns the mixture into soap for the hair.

The clay, oil, beeswax, and lye become a liquid shampoo that's then poured into a bin and wheeled into a drying room, where it sits for two days.

Then it's cut and packaged into biodegradable boxes.

Mass-produced shampoo often uses artificial foaming agents like sodium lauryl sulfate.

Those go down the drain and can end up in the oceans.

Saunders says that's partly why customers want to buy her bars, which break down safely in nature.

She sells 100,000 of them a year.

But that's still only a tiny fraction of the 2-billion-dollar shampoo market.

It's extremely hard to get people to understand shampoo bars.

People are beginning to understand, but it is still very fringe.

Fringe because mass-market shampoo in plastic bottles dominated store shelves and TV ads for decades.

A new shampoo with vitamins, minerals, protein, and a...

But experts say a growing number of consumers, especially millennials, now want to buy biodegradable beauty products.

This is something that we are seeing happen in the shampoo category where "how" matters, like how the product is made.

Lush Cosmetics scaled for mass production years ago, and now sells about 20 million dollars' worth of shampoo bars every year.

We have seen, really, a shift from customers, and more and more folks looking at how they can be more environmentally friendly in their own lives.

Lush showed us how they make one of their top-sellers, the Seanik shampoo bar.

This 12-disc lasts for 80 washes and replaces about three shampoo bottles.

Sea salt, lemon and orange flower oils, and two types of seaweed.

These are dried sheets of nori seaweed being fed into a paper shredder.

They're added right at the end.

The smell is quite strong; it'll remind you of sitting on the beach, hanging out by the ocean.

The same kind of food coloring used in M&M's makes it pop on the shelves and online.

Lush has sold 41 million of these Seanik bars since 2005.

That's equivalent to about one-fifth of all the shampoo bottles Americans buy in a year.

Multinational brands like Procter & Gamble and L'Oreal are also getting into the natural shampoo market.

We spoke to Sonika Malhotra, co-founder of Unilever's "Love Beauty & Planet" line that launched in 2018.

The shampoo bars sell in more than 40 countries and in retailers like Target and Walmart.

So we need to track technologies where we are able to find materials that, sort of, replicate all of these values, these properties that this material has.

And that's not easy.

Unilever shampoo bars are still niche compared to their legacy brands like Suave and Tresemme.

But the pressure to cut plastics is on.

In 2019, a Greenpeace campaign tagged manufacturers on widely circulated photos of trash,

and singled out Unilever as a major source of plastic garbage, along with Coca-Cola, Pepsi, and Nestle.

Now we can pick up our smart devices and look, like, hey, what's the brand's opinion on this?

What does the brand do to limit waste?

Unilever signed a commitment to eliminate single-use packaging, but little progress has been made.

And plastics contribute to climate change.

They're made with fossil fuels and emit greenhouse gases throughout their life cycle.

Many countries have banned certain types of plastic packaging.

When we think about real solutions, we have to look at systems' change.

And who is accountable for that?

It's corporations and industry.

Break Free From Plastic runs beach cleanups where volunteers tally up the trash associated with specific brands.

Break Free's global head of communications says all this plastic garbage won't go away with just shampoo bars.

These sorts of products are still putting the onus on individuals.

There is something really strong about wallet power.

But it is a drop in the bucket in terms of the solution to be focused on.

And small businesses like Jill's face obstacles to scaling up, like steep shipping costs and expensive ingredients.

Her bar costs three times as much as Unilever's.

Despite the challenges, Jill says her customer base is growing.

Business is getting better and better and better as a result of the zero-waste consciousness and people's awareness that biodegradability is very important.

So, the future looks extremely bright.