Jobs › Ecolab

Sr. Lab Technician

Ecolab · Naperville, IL · $55,400–$83,200 a year · Full time

Posted Sep 21, 2026 · We last checked this listing on Oct 6, 2026

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Likely interview questions for this role

Written from this job description, not a generic list. Each one notes what the interviewer is really checking.

About your past

Tell me about a time you trained someone on a lab technique. How did you know they were ready?

What they are checking: Whether they can teach well and verify understanding rather than just demonstrating once.

How do you keep a lab stocked and organized so work doesn't stop?

What they are checking: Whether they plan ahead for supplies and maintenance rather than reacting when something runs out.

Tell me about a time you noticed something unusual in a sample result and followed up on it.

What they are checking: Whether they think about what results mean rather than just recording numbers.

What would you do

An instrument starts giving strange readings in the middle of a busy day. What do you do?

What they are checking: Whether they stop and troubleshoot instead of continuing to produce questionable results.

A scientist asks you to run a test in a way that skips a step in the procedure. How do you respond?

What they are checking: Whether they will raise concerns about procedure changes and document deviations properly.

How do you balance routine testing with special requests from scientists?

What they are checking: Whether they can prioritize and communicate turnaround times clearly when requests compete.

About the work

Walk me through how you would prepare and analyze a corrosion coupon.

What they are checking: Whether they know the actual handling, cleaning and weighing steps that make the results reliable.

What's your experience handling reverse osmosis membranes or deposit samples in the lab?

What they are checking: Whether they have worked with the kinds of field samples this lab sees and know how to avoid damaging them.

How do you make sure the results you enter into LIMS are accurate and consistent?

What they are checking: Whether they have habits that protect data integrity, since others make decisions from those records.

What lab safety risk assessments have you followed, and what made them useful?

What they are checking: Whether they understand safety procedures as practical tools rather than paperwork.

Practice this interview out loud.

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The full job description

As published by Ecolab.

Want to build a brighter, bolder future and cultivate your career? Join Ecolab’s team and help create a world in which we all thrive. Ecolab is seeking a Senior Lab Technician to join our team in Naperville, IL. As a Senior Lab Technician, you’ll support a wide range of laboratory operations—from preparing and analyzing samples to maintaining equipment and mentoring new team members. You’ll collaborate closely with scientists and technicians to ensure accurate testing, troubleshoot challenges, and contribute to a safe, organized, and high-performing lab environment. How You’ll Make an Impact: • Follow all safety procedures and risk assessments • Prepare samples such as corrosion coupons, press fabrics, solid deposits, resins, or reverse osmosis membranes • Conduct a variety of materials and chemical testing procedures by working with laboratory instruments to gather results • Record and analyze testing results consistently and accurately in Laboratory Information Management System (LIMS) • Train new members of the team in lab techniques after gaining expertise in those areas • Maintain equipment in operating condition and order supplies and services as needed • Prepare and stock supplies for daily lab work • Routine laboratory cleaning Position Details: • Plant Location:   Naperville, IL • Work Week & Shift:   Monday - Friday 8:00am - 4:30pm. What is Unique About This Role: • The support of an organization that believes it is vital to include and engage diverse people, perspectives and ideas to achieve our best • Be part of a company that values a culture of safety that includes top-notch safety training and personal protective equipment Minimum Qualifications: • Bachelor’s degree in Chemistry, Biology, Chemical Engineering, or relevant science discipline • 2 years of lab-based experience • Immigration sponsorship is not offered for this role Preferred Qualifications: • Proficiency and expertise in utilizing, calibrating, and maintaining technical laboratory equipment • Experience with statistical methods for data analysis and trending • Strong interpersonal communication skills, including excellent oral and technical writing capabilities • Experience multi-tasking and managing numerous projects simultaneously • Experience using Microsoft Office Suite (Word, Excel, Outlook, and PowerPoint) What’s in it For You: • Starting on Day 1 : Access to our comprehensive benefits package including medical, dental, vision, matching 401K, company-paid pension, stock purchase plan, paid parental leave, select discounted childcare resources, and more! • The opportunity to take on some of the world’s most meaningful challenges, helping customers achieve clean water, safe food, and healthy environments • The ability to make an impact and shape your career with a company that is passionate about growth • The support of an organization that believes it is vital to include and engage diverse people, perspectives, and ideas to achieve our best. About Ecolab: At Ecolab, we prioritize our talent-first philosophy by creating the most capable and diverse team to excel at our nearly three million customer sites. Building on a century of innovation, our 48,000 associates help deliver comprehensive science-based solutions, data-driven insights and world-class service to advance food safety, maintain clean and safe environments, and optimize water and energy use, and improve operational efficiencies and sustainability for customers in the food, healthcare, life sciences, hospitality and industrial markets in more than 170 countries around the world. Our solutions not only enhance operational efficiency but also contribute to sustainability and public health, making a positive impact on the world. We are committed to eliminating unnecessary complexities and embracing a beginner's mindset, continuously seeking new perspectives and innovative solutions to stay ahead in a rapidly changing world. Annual or Hourly Compensation Range: The salary range is $55,400 - $83,200. Many factors are taken into consideration when determining compensation, such as experience, education, training, geography, etc. We comply with all minimum wage and overtime laws. Benefits Ecolab provides the following benefits: medical, dental, vision, life insurance, accident insurance, critical illness insurance, hospital indemnity insurance, auto insurance, home insurance, pet insurance, identity theft protection, short-term and long-term disability, 401k, pension plans, retirement health care benefits, short-term incentives, vacation (12 days), holidays, parental leave, employee stock purchase plans (Full-Time Associates), discount on day care services and caregiver services, adoption assistance, group legal services, employee assistance program, employee discount program, and education assistance program, on-Site childcare and fitness facilities may be available at select Ecolab locations. Click here  for additional benefits information.  If you are viewing this posting on a site other than our Ecolab Career website, view our benefits at jobs.ecolab.com/working-here . Potential Customer Requirements Notice To meet customer requirements and comply with local or state regulations, applicants for certain customer-facing roles may need to: - Undergo additional background screens and/or drug/alcohol testing for customer credentialing. Americans with Disabilities Act (ADA) Ecolab will provide reasonable accommodation (such as a qualified sign language interpreter or other personal assistance) with our application process upon request as required to comply with applicable laws. If you have a disability and require accommodation assistance in this application process, please visit the Recruiting Support link in the footer of each page of our career website.

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