- API 936 is API's Individual Certification Program credential for refractory personnel, not a design or engineering standard by itself.
- The exam has 85 total questions (75 scored, 10 unscored pretest) in 195 minutes, closed-book, scored on a 200-500 scale with 400 to pass.
- Content is organized into four domains: Roles and Responsibilities, Laboratory Testing Procedures, Materials and Installation Requirements, and Installation...
- No prior experience level is mandatory - newcomers to the industry can sit for the exam.
What Is API 936, Exactly?
API 936 refers to Refractory Personnel Certification (API 936), a credential administered through the American Petroleum Institute's Individual Certification Programs (ICP). It verifies that an individual understands the roles, testing procedures, materials, and inspection practices tied to refractory installation and quality control in petroleum and petrochemical facilities. The name "API 936" is shared informally across a few unrelated things in the industry, so if you searched for this term and landed on unrelated salary numbers or fee schedules elsewhere, be cautious - this article, and this site, deal exclusively with the ICP credential described here.
If you're still deciding whether this certification fits your career path, our ROI analysis of the API 936 certification walks through the trade-offs in more depth. For a plain-language breakdown of the acronym itself, see API 936 Meaning and What Does API 936 Stand For?.
Who Administers the Certification
The American Petroleum Institute manages API 936 through its Individual Certification Programs division. API sets the Body of Knowledge (BOK), maintains the required reference list, and publishes exam statistics annually. The current BOK and publication effectivity window runs from April 2025 through December 2026, which means the reference editions listed below are the ones you should study from right now - not older versions you might find in a used bookstore or an outdated training packet.
The required references for the current cycle are:
- API Standard 936, fifth edition, March 2024
- API 975, first edition, November 2021
- API 976, first edition, March 2018
- ASTM C113-14 (2019)
- ASTM C133-97 (2021)
- ASTM C181-11 (2018)
- ASTM C704-15 (2022)
Every scored question on the exam should be traceable to one of these documents. If a study resource references anything outside this list, treat it skeptically.
The Four Body of Knowledge Domains
API organizes the exam content into four domains. Understanding what each one actually tests - not just its title - is the difference between generic studying and targeted preparation. Our complete guide to all four content areas breaks these down question by question, but here's the shape of each one.
Domain 1: Roles and Responsibilities
Covers who does what on a refractory project - owner, contractor, inspector, and testing lab responsibilities as defined in the reference standards.
- Distinguishing inspector duties from contractor duties
- Documentation and reporting responsibilities during installation
Domain 2: Laboratory Testing Procedures
Tests knowledge of the ASTM test methods used to evaluate refractory materials, including sample preparation and interpretation of results.
- ASTM C113, C133, C181, and C704 test procedures and purposes
- What each test measures and why it matters for material acceptance
Domain 3: Materials and Installation Requirements
Focuses on refractory material types, mix requirements, curing, and installation methods described in API 936 and API 976.
- Material selection criteria tied to service conditions
- Installation sequencing and curing/drying requirements
Domain 4: Installation Inspection and Quality Control
Covers inspection checkpoints, acceptance criteria, and quality control practices applied during and after installation.
- Hold points and inspection timing
- Nonconformance identification and corrective steps
Key Takeaway
Don't study the domains as isolated buckets - Domain 2's lab tests directly inform the acceptance criteria you'll need for Domain 4's inspection questions. Cross-referencing them while you study mirrors how the exam actually blends concepts.
Exam Format and Scoring
The API 936 exam consists of 85 total questions, of which 75 are scored and 10 are unscored pretest items you can't identify during the exam. You get 195 minutes to complete it, and it is closed-book multiple choice. API has indicated it is gradually introducing alternative item types across its ICP exams, so don't assume every question will look like a traditional four-option multiple choice item forever.
Scoring is reported on a scaled range of 200 to 500, and you need a scaled score of 400 to pass - this is not the same as answering 400 out of 500 questions correctly, and it is not a simple percentage. For a full explanation of how the scaling works and what it means for how many questions you can miss, see our detailed passing score breakdown.
No papers or personal reference materials are allowed in the exam. Test centers provide a calculator and scratch paper; remote ProProctor sessions provide digital equivalents and require a system-readiness check beforehand, so test your setup well in advance if you're testing from home or office.
| Exam Detail | Specification |
|---|---|
| Total questions | 85 (75 scored, 10 unscored pretest) |
| Time allowed | 195 minutes |
| Format | Closed-book, multiple choice (with alternative item types being phased in) |
| Passing score | 400 on a 200-500 scale |
| Delivery | Prometric test centers or ProProctor remote proctoring |
Curious how difficult this actually is in practice? Our difficulty guide and pass rate analysis cover the December 2025 administration data in detail.
Registration, Fees, and Testing Options
Registering for API 936 involves submitting an application through API's ICP system and paying the applicable fee. Initial application fees are USD 450 for API members and USD 625 for nonmembers. Recertification fees are lower - USD 320 for members and USD 430 for nonmembers. If you need to reschedule your exam through API, that carries a separate USD 200 reschedule application fee, and submitting your application late also incurs a USD 200 late fee.
Once approved, you'll schedule your sitting at a Prometric test center or through remote ProProctor proctoring, depending on availability and your preference. For a complete cost breakdown including scenarios where fees stack up (late applications, reschedules, recertification cycles), see our full pricing breakdown. If you're mapping out when to apply and test, the exam dates and scheduling guide covers testing windows and deadlines in more detail.
Who Actually Needs API 936?
Employers in refinery, petrochemical, and heavy industrial maintenance typically look for API 936 when hiring or promoting inspectors, quality control personnel, and refractory contractors who need documented competency in installation oversight. Because the exam covers roles and responsibilities alongside technical material and testing knowledge, it's relevant to people on both the contracting side and the owner/inspection side of a project.
One detail that surprises a lot of first-time applicants: API does not require a minimum level of petroleum or petrochemical experience to sit for the exam. Applicants entering the industry can apply, and a formal preparation course is not mandatory - though most candidates still benefit from structured study given the breadth of the reference materials. If you want the specifics on eligibility rules and any documentation you'll need to submit, read our eligibility and requirements guide.
For candidates weighing whether the credential will actually open doors, our earnings analysis and the API 936 jobs overview look at where this certification tends to matter most on a resume.
How to Prepare Without Wasting Time
Because the exam draws from a fixed, published reference list, effective preparation looks less like generic test-taking strategy and more like methodical document mastery. Start by reading API 936 fifth edition cover to cover, since it anchors most of Domains 1, 3, and 4. Then work through the ASTM test methods (C113, C133, C181, C704) specifically for Domain 2 - these are dense but narrow, and memorizing what each test measures pays off disproportionately given how concentrated that content is.
API 936 and API 976 fundamentals
- Read API 936 fifth edition in full, taking notes by domain
- Map API 976 sections to Domain 3 installation requirements
ASTM test methods and API 975
- Study C113, C133, C181, and C704 individually - purpose, procedure, and what results indicate
- Review API 975 for context on Domain 1 and Domain 2 overlap
Integration and practice
- Run timed practice questions covering all four domains
- Revisit weak domains identified through practice performance
For a more detailed week-by-week plan with specific reading targets, our study guide for passing on your first attempt goes further than this overview. It's also worth reviewing a condensed reference before test day - the one-page review of must-know facts is built for that final pass. And when you're ready to test your recall under exam-like time pressure, practice tests on our main site simulate the 195-minute, 85-question format so you're not caught off guard by pacing on test day.
Key Takeaway
Spend disproportionate time on the ASTM test methods early - they're the most narrowly defined content and the easiest to lock in with confidence before moving to the broader API 936 material.
Keeping the Credential Active
API 936 certification is valid for three years. Renewal is handled through application and payment of the recertification fee - there's no employment verification step required, which simplifies the process considerably. You can apply for renewal starting 90 days before your certification expires, and if you miss that window, a 90-day grace period exists after expiration, though a late fee applies during that time.
Separately, every six years, certified individuals must complete an online open-book recertification quiz: 25 questions, a four-hour window, with up to three pauses allowed and one retry if needed. This is distinct from the standard three-year renewal and is designed to confirm ongoing familiarity with updated standards without requiring a full closed-book retest.
If you let your certification lapse beyond the grace period, the shortcuts disappear - you'll need to submit a brand-new application and sit for the full examination again, exactly as you did the first time.
If you're weighing the practical side of applying, testing, and renewing, our broader API 936 Certification overview ties registration, exam day, and renewal together in one place. And for a deeper naming clarification if you've seen the acronym used elsewhere, What Does API 936 Mean? and What Is A API 936? address common confusion points directly.
Frequently Asked Questions
No. Applicants of any experience level, including those new to the petroleum or petrochemical industry, can apply. A preparation course is not required either, though most candidates study the required references thoroughly before testing.
The exam has 85 total questions - 75 scored and 10 unscored pretest items you cannot distinguish during the test - administered over 195 minutes in a closed-book, multiple-choice format.
You need a scaled score of 400 on a 200-500 scale. This is not a raw percentage of correct answers, so exact question counts needed to pass can vary by exam form.
Certification is valid for three years. You can apply for renewal starting 90 days before expiration, and a 90-day grace period with a late fee is available if you miss that window.
You can sit for the exam at a Prometric test center or remotely through ProProctor proctoring. Remote candidates should complete a system-readiness check beforehand since papers and personal materials aren't allowed either way.