It’s back-to-school season, a $27.8 billion industry and the second largest shopping season in the U.S. after Christmas. Most of what parents buy is made of plastic and often winds up as landfill. Heather Itzla, 50, and Nikki Kozlowski, 27, are business partners in San Francisco with a mission to eliminate “plastic pollution” by providing schools and families with innovative and recyclable alternatives.

J.: Your company, Wisdom Supply, is trying to change the back-to-school culture of buying products made of plastic, vinyl and other non-recyclable materials that become “forever-lasting waste,” as you put it. How do you identify which products are the biggest culprits, and how do you remedy that?

Heather: At the end of the school year, we do what we call a locker cleanout. We’ll do a waste audit and document what the students are throwing out. It’s the same every single year — mostly unused stuff. The culture is, you’re going to go right back out to Target or Staples the next year and buy it brand-new again. They make it look fun and shiny and sparkly. The marketing is set up that way, and the teacher lists are set up that way, and it’s trashing the planet. We stock and ship plastic-free, recyclable school supplies, all designed to stay out of the waste stream.

When and how did you start?

Heather: Seven years ago, when my two sons were in middle school. Every day when I was out walking my dogs, I’d pick up every piece of plastic I found and then document it on my blog (thereisnoaway.net). Everyone knew I was on my plastic awareness campaign. Because the school was so small, they allowed me to purchase all of the supplies for all of the students, and the families reimbursed me. Another school got wind of it and asked if we could do that for their school. That’s when it went from being a volunteer effort to having a website and a way to take payments. Now we’re on our third year of doing deliveries.

How did you two meet?

Nikki: The world of ocean conservation in San Francisco is pretty small and we just kept running into each other. We got together and agreed that our main goal is to reduce as much plastic pollution as two humans possibly can. We got to work the next day and have been working every day since.

So this is a full-time endeavor for both of you?

Heather: It’s full time plus-plus-plus extra. We personally pack every order, drive the delivery trucks to the schools, receive all of the shipments and handle all of the inquiries, write the website copy and tend to all of the web maintenance and sweep the warehouse floors. We take big plastic crates filled with the supplies the schools ordered, help them get set up, and a few days later we circle back and collect the bins so they’re left with no trash, no boxes to break down, no plastic, no packaging.

And teachers can create custom kits of zero-waste supplies for their classes on the website?

Nikki: We’ve built the system in such a way [for parents] that you can add a kit to your cart and delete what you already have or don’t need or don’t want to purchase.

What are some earth-friendly alternatives to typical supplies like highlighters and pencil cases?

Heather: We had a tough time figuring out pencil boxes. The plastic pencil boxes and zipper pouches are so big. When you have a big vessel like that, you tend to fill it up, so you have kids walking around with big boxes in their backpacks filled with colored pencils and fidget spinners and doodads and weird stuff. To have a fully recyclable aluminum pencil tin, we had to have them made. It was the first time we developed our own product. We had it sized specifically to fit just a few things — one pencil, a sharpener, your nonplastic highlighter, a pen, and that’s it.

When kids are given their own daily planner, every one of those is going to landfill. It’s dated and trash by the end of the year no matter what. So we designed and made our own that would be 100 percent recyclable. They’re stripped to the barest part of what you need, and you get pages as you need them.

We found a recyclable binder that you can take the cover off, put it in paper recycling and replace it with a new cover, so none of it goes to landfill.

At the end of the school year when we’re going through the garbage, we see those marble-covered composition books, which are typically 100 or more pages. If they have 15 pages written on them, it’s like a miracle. We’re developing a range of notebooks that are 20 or 24 pages.

I still have a stack of those barely used composition books because I feel bad about getting rid of them. My kids are 20 and 23!

Heather: We hear this a lot from parents, this guilt about not wanting to throw things away. A lot of people want to donate half-used supplies to communities that need them. Somehow there’s a transference of guilt. But just because you’re giving it away doesn’t fix the problem. You should be buying better stuff, period.

You have 20 Bay Area schools participating, including Brandeis Marin. How do you make those connections?

Heather: Schools are like fortresses, there’s no way of getting in from the outside as a vendor. Our saying is “It just takes one” — one parent, one student, one teacher who understands what we’re doing and can open the door for us. Once we’re in, it all starts moving quickly.

You’ve mentioned the Jewish concept of “ba’al tashchit,” or “do not destroy.” What are some of your other spiritual motivations?

Nikki: My grandmother is a Holocaust survivor, and I actually have a tattoo of tikkun olam, fixing the world. That’s the DNA and core of this company. If we can repair what little portion we have on this Earth, then we’re going to just work on that wholeheartedly.

How does this work affect you emotionally?

Heather: It’s devastating, but if I weren’t working on it every day, it would be overwhelming. And then to be working with a business partner, there’s a great deal of therapy in that, and honestly a lot of dark humor comes from it.

What would you recommend to people who want to do their part?

Nikki: The most environmental thing you can do is use what you already have at home. That’s the message we’re trying to get across to folks: Don’t buy it if you don’t need it. And pick one thing. It doesn’t have to be a whole systems change, it doesn’t have be an entire school and every single product or a whole office. It could just be highlighters, it could just be one thing, and that makes a difference.