SRC & C. Perfringens Screening — Explained

Parents have been asking about bacteria screening and how we test our formula at Nara. We know that your baby's safety is incredibly important. So let’s break down sulfite-reducing clostridia (SRC) screening.

SRC & C. perfringens screening 

SRC screening isn’t a test for one specific bacteria, but for a class of bacteria that can form spores; these spores can survive even after pasteurization. Alongside SRC, Nara also screens every batch of infant formula for C. perfringens, another helpful marker for spore-forming bacteria.

These tests are a screening tool — a way to check whether everything in the manufacturing process went as planned.

Think of it like a smoke detector. It doesn’t tell you the exact source of smoke, but it alerts you early so you can investigate.

Can you directly test for Botulinum?

When SRC comes up, parents naturally ask, “‘So why not test directly for botulinum?”

Here’s the answer from our Regulatory & Science team:

There is no routine, one-step rapid test for botulinum. Detecting it takes a complex, multi-stage process and requires sophisticated tests and equipment. That’s why screening tools like SRC and C. perfringens can provide great insights.

While the screening tests don’t directly detect botulinum, they’re an important early warning system. If anything were ever to look off, an investigation could start long before it becomes a safety concern.

That’s why Nara has used SRC and C. perfringens screening tools from Day 1. 

 

What about pasteurization?

Pasteurization is extremely effective. Formula manufacturing uses processes that reduce bacteria by over 99.999%, or what microbiologists call as at least a 5 log reduction. But, that’s just one step. If your raw material or the environment is contaminated, pasteurization itself cannot be a remedy. 

Therefore, Nara doesn’t rely on just one safeguard. Our overall safety program is essential to identify and help eliminate any problem at its source.

That’s why we combine pasteurization, ingredient controls, environmental monitoring, process controls, and third-party testing — to create multiple layers of assurance.

 

Nara’s full safety framework

When people first hear “SRC testing,” it sounds like a process you could just add on easily. But SRC screening is an effective tool only when it is part of a whole safety framework.

At Nara, that framework includes:

1. Testing raw ingredients

2. Sampling and testing of the manufacturing environment

3. Testing and validating every step in manufacturing

4. Using labs with validated protocols

5. Testing finished product

6. Having established plans for follow-up testing if anything ever looks unusual

7. Implementing the follow-up plan in a strict timing windows to ensure results stay accurate and meaningful

A stand-alone test is a quick-fix, but a multi-level control program helps you identify the problem and prevent it from happening. 

 

SRC and C. perfringens are voluntary tests 

Importantly, these screenings aren’t a requirement in the formula industry, and implementing them at Nara didn’t happen overnight. We built these tests intentionally into our process from the very beginning with our manufacturing partners in Germany, because we wanted these multiple layers of quality assurance — not just a final test at the end. 

This means all batches of Nara Organics infant formula have been screened for SCR and C. perfringens right from the start — this isn’t something we’re just now beginning to do. We’re happy to see other formula brands start to implement these screenings, it raises the safety standards of the formula industry. 

 

Nara meets EU and U.S. food safety standards 

Nara has an incredibly rigorous safety program. This is in part because Nara is FDA registered and made in Germany, which means we meet both U.S. and EU food safety standards — and the EU has some of the strictest in the world, especially for infant formula.

Here’s one of the biggest differences:

The EU sets maximum allowable levels for certain contaminants like lead, cadmium, and arsenic. While the U.S. also regulates these to the lowest possible levels, it doesn’t have a set limit for these in infant formula.

Because we manufacture in Europe, every batch of Nara is tested to meet EU levels. 

 

3rd party testing 

Every batch of our formula goes to an ISO-accredited third-party lab where we also test for other substances. ISO stands for International Organization for Standardization. 

They test for:

• Heavy metals — like lead, cadmium, and arsenic, and mercury
• Environmental contaminants — BPA, pesticide residues, acrylamide
• Microbial checks — listeria, salmonella, cronobacter and other bacteria including SRC and C. perfringens

If Nara’s formula ever exceeded EU limits, it would not be sold to parents and families. 

Additionally, the Clean Label Project independently tests our formula for 500+ chemicals of concern. We’ve earned both their Purity Award and their Pesticide-Free Award.

 

Your baby's safety is always our first priority

At Nara, we built an extensive safety system intentionally and proactively— not reactively — so parents can feel confident in every batch of Nara Organics. We want you to be able to trust that Nara is doing everything we can, from the ground up.