What is Sertu? A Guide to Intensive Halal Cleaning and Using RLU

Sertu is an Islamic method of spiritual purification and cleaning, specifically used when surfaces or objects are contaminated with major najis (impurities). 

This practice is rooted in Islamic jurisprudence, ensuring both physical and spiritual cleanliness as per Islamic concepts. It is particularly relevant in halal certification processes where cross-contamination with najis, such as pork, blood, or intoxicants, must be addressed.

The term Sertu is derived from the Arabic word “Satr,” which means “to clean or purify.” This process is essential for restoring the permissible (halal) status of objects or areas contaminated with major impurities.

In this guide, we will dive comprehensively into what sertu is  its significance in maintaining halal integrity, the step-by-step procedure for performing sertu. 

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When is Sertu Necessary?

Sertu is required when a surface, object, or area is contaminated by major najis (impurities). These impurities are considered severe according to Islamic jurisprudence and have specific guidelines for removal to restore spiritual and physical cleanliness. The need for sertu arises in situations involving the following contaminants or circumstances:

1. Contamination with Najis al-Mughallazah (Severe Impurities)

The highest level of najis, Najis al-Mughallazah, primarily refers to substances related to pigs and dogs. This includes:

• Pig flesh, skin, saliva, or any bodily discharge.
• Dog saliva, which is explicitly mentioned in Islamic texts as requiring a unique cleansing procedure.

Sertu is mandatory for any object or surface contaminated by these substances. Without sertu, the item cannot regain its permissible (halal) status.

2. Cross-Contamination in Halal Environments

In facilities producing halal-certified products, cross-contamination is a critical issue. Sertu becomes necessary when:

• Halal production lines are exposed to materials containing pork derivatives, alcohol, or najis.
• Shared equipment, utensils, or packaging areas are used for halal and non-halal products.
• Storage spaces or transport containers for halal goods come into contact with major najis.

Example: In a food manufacturing facility, if equipment used for halal production is also used to process pork products, sertu must be performed before switching back to halal production.

3. Human Error or Accidental Contact

Accidental contamination, such as:

• Spills involving najis substances.
• Incorrect handling by employees where najis is transferred to halal products or surfaces.
• Mishandling of raw materials or cross-contact during transportation.

Example: If an employee inadvertently uses gloves contaminated with pork residue to handle halal ingredients, all affected surfaces and materials must undergo sertu.

4. Preparation or Handling of Non-Halal Items

In kitchens, sertu is necessary when:

• Utensils, cooking surfaces, or ovens used for non-halal foods (e.g., pork or alcohol) need to be repurposed for halal use.
• Accidental mixing of non-halal and halal foods occurs.

Example: In a cosmetics manufacturing facility, a mixer used to produce a lotion containing pig-derived glycerin must undergo sertu before it can be used to produce halal-certified skincare products. 

Sertu Procedure: Step-by-Step Guide

The sertu process, derived from Islamic jurisprudence, involves both physical and spiritual purification of surfaces or objects contaminated with major najis (impurities). It is a precise, structured method aimed at restoring the halal status of the affected area. 

Below is a detailed step-by-step procedure for performing sertu, incorporating both traditional principles and modern advancements.

Step 1. Assess the Contamination

• Identify the Contaminant: Confirm that the surface or object is contaminated with Najis al-Mughallazah (major impurities such as pig-related substances or dog saliva).
• Determine the Extent: Evaluate the level and area of contamination to plan the cleaning process.

Step 2. Prepare the Cleaning Solution

• Traditional Component: Mix water with soil (earth). Soil serves as the purifying agent based on Islamic guidance:
  • “Wash it seven times, one of which shall be with soil.” (Prophetic tradition)
• Modern Adaptation: If soil is unavailable, dry detergent or approved cleansing agents can be used, provided they do not contain najis or harmful substances.
  • Ensure the cleaning agent is halal-certified if used in halal-certified environments.

Step 3. Initial Cleaning

• Remove Visible Najis: Physically remove all visible traces of najis using clean, disposable tools. Dispose of any solid impurities properly to avoid further contamination.
• Initial Wash: Rinse the contaminated area thoroughly with water to remove loose particles.

Step 4. Perform Sertu with Seven Washes

• First Wash (with Soil):
  • Apply the water-soil mixture to the contaminated area.
  • Scrub thoroughly to ensure that the soil interacts with all surfaces.
  • Allow the soil to adhere momentarily, as it acts as the key agent for spiritual purification.
  • Rinse with clean water to remove soil residue.
• Subsequent Six Washes:
  • Rinse the surface six more times with clean, flowing water.
  • Each wash must remove any remaining impurities or cleaning residues.
  • Ensure the water flows off the surface and does not pool, as stagnant water may retain najis particles.

Step 5. Verify Cleanliness

• Physical Inspection: Check for any residual impurities. The area should appear physically clean with no traces of najis.
• ATP Testing (Optional but Recommended):
  • Use an ATP (adenosine triphosphate) monitoring system to confirm cleanliness.
  • Acceptable Relative Light Units (RLU) score: ≤ 10.
  • If the RLU exceeds 10, repeat the sertu process until compliance is achieved.

Step 6. Dry and Restore the Area

• Air Drying: Allow the area to dry naturally or use clean, uncontaminated cloths.
• Restoration:
  • For equipment: Reassemble and test functionality if disassembled for sertu.
  • For surfaces: Mark the area as clean and ready for halal production or use.

Step 7. Document the Process

• Maintain detailed records of the sertu procedure, including:
  • The reason for performing sertu (e.g., type of contamination).
  • Materials and cleaning solutions used.
  • Results of physical inspections and ATP testing.
  • Date, time, and personnel involved.
• This documentation may be required during halal certification audits.

Step 8. Prevent Future Contamination

• Implement Halal Critical Control Points (HCCPs):
  • Segregate halal and non-halal items in storage, production, and handling areas.
  • Train employees on proper handling and cleaning protocols.
  • Use dedicated equipment and tools for halal operations where possible.

Practical Applications of Sertu

In modern manufacturing contexts, sertu ensures that production lines, equipment, and facilities comply with halal standards, making them suitable for producing halal-certified products. Below is an in-depth look at practical applications of sertu across various manufacturing scenarios.

1. Food and Beverage Manufacturing

In the food and beverage industry, cross-contamination can occur due to shared equipment or storage spaces. Sertu is essential when manufacturing facilities process both halal and non-halal products.

Examples:

• Shared Mixers: A mixer used to produce a sauce containing wine or pork-derived ingredients must undergo sertu before being used for halal-certified sauces.
• Packaging Lines: If a conveyor belt is used for packaging snacks containing pork gelatin, it must be purified with sertu before packaging halal-certified snacks.
• Storage Containers: A storage tank previously containing non-halal products, such as lard-based shortening, must be cleansed using sertu before storing halal oils or fats.

Steps:

1. Dismantle the equipment or isolate the area for cleaning.
2. Perform sertu by applying the water-soil mixture for the first wash, followed by six clean water washes.
3. Use ATP testing to ensure all residues are removed, achieving an RLU score ≤10.

2. Pharmaceutical Manufacturing

Pharmaceutical companies producing capsules, syrups, or vaccines may encounter contamination risks if non-halal substances like pig-derived gelatin or alcohol are involved. Sertu ensures that equipment used in such cases can be restored to a halal-compliant state.

Examples:

• Encapsulation Machines: If capsules made from pig-derived gelatin are produced, the encapsulation machine must undergo sertu before manufacturing halal-certified capsules.
• Mixing Tanks: Tanks used for alcohol-based syrups must be cleaned via sertu before being used for halal-compliant formulations.

Steps:

1. Clean the tank or machine with water to remove visible najis.
2. Conduct sertu by scrubbing with the water-soil solution and rinsing six additional times.
3. Inspect thoroughly to confirm that the equipment meets halal cleanliness standards.

3. Cosmetics and Personal Care Manufacturing

The cosmetics industry often uses animal-derived ingredients, some of which may be najis, such as pig-derived glycerin or enzymes. Sertu is necessary to cleanse the production line and ensure compliance with halal certification requirements.

Examples:

• Mixers and Blenders: A mixer used to produce lotions containing non-halal glycerin must be purified with sertu before producing halal-certified skincare products.
• Filling Machines: Equipment filling lip balms with najis-derived components must be cleansed using sertu before handling halal formulations.

Steps:

1. Dismantle all removable parts of the equipment for effective cleaning.
2. Apply the sertu procedure, ensuring the water-soil mixture reaches all contaminated areas.
3. Document the process and maintain records for halal certification audits.

4. Chemical Manufacturing

In chemical production, najis substances such as pig-derived stearates or alcohol-based solvents may contaminate equipment. Sertu is critical for restoring the equipment for halal-compliant chemical manufacturing.

Examples:

• Reactors and Vessels: Reactors used to process non-halal solvents must undergo sertu before being used to produce halal-compliant products like food-grade emulsifiers.
• Pipelines and Valves: Pipelines transporting najis chemicals must be purified through sertu before transferring halal-certified raw materials.

Steps:

1. Flush the system with clean water to remove residues.
2. Introduce the water-soil mixture into the equipment and allow it to circulate.
3. Perform subsequent rinses with clean water and verify cleanliness using ATP testing.

5. Logistics and Warehousing

Contamination risks extend beyond production lines to storage and transportation. Sertu can be applied in logistics and warehousing operations to maintain halal compliance.

Examples:

• Storage Facilities: Warehouse racks or containers storing najis products, such as pork-based products, require sertu before storing halal-certified goods.
• Transport Vehicles: Trucks used to transport non-halal items must be cleansed through sertu before being repurposed for halal-certified products.

Steps:

1. Remove any visible contaminants and clean the affected areas with water.
2. Apply the sertu procedure, paying attention to corners and crevices.
3. Inspect and approve the area for halal use.

6. Shared Facilities in Multi-Product Plants

In facilities producing both halal and non-halal products, sertu is indispensable to prevent cross-contamination between production cycles.

Examples:

• Baking Facilities: A bakery using lard-based shortening for some products must clean ovens and utensils with sertu before preparing halal-certified baked goods.
• Meat Processing Plants: A meat processing plant handling pork must perform sertu on its cutting and grinding equipment before processing halal meat.

Steps:

1. Schedule production to ensure non-halal products are processed last.
2. Conduct sertu on all equipment and areas exposed to najis.
3. Document the sertu process as part of the Halal Assurance System (HAS).

Consult AHF for Halal Certification

Our team of halal certification specialists is equipped to help you implement sertu procedures, manage cross-contamination risks, and ensure your products meet global halal standards.

Contact us today to ensure your manufacturing operations align with halal standards. Call us at +1 (630) 759-4981 or email us at info@halalfoundation.org.

Frequently Asked Questions (FAQs) 

1. What is sertu, and why is it necessary in manufacturing?

Sertu is an Islamic purification process for removing major impurities (najis). It is essential for restoring halal compliance in contaminated manufacturing equipment or facilities.

2. Can sertu be performed on shared equipment in manufacturing?

Yes, sertu can be used to purify shared equipment after processing najis substances. A rigorous cleaning process ensures no traces of impurities remain.

3. How does AHF support businesses in performing sertu?

AHF provides customized sertu protocols, employee training, and on-site assessments to help businesses implement effective purification procedures.

4. What industries commonly use sertu?

Industries like food, pharmaceuticals, cosmetics, and chemicals often use sertu to address cross-contamination risks and maintain halal compliance.

5. Is sertu a requirement for halal certification?

Yes, if contamination with najis substances occurs, sertu is mandatory to restore halal compliance before certification can be granted.6. How does

6.AHF ensure the sertu process meets halal standards?

AHF experts audit and verify sertu procedures using global halal guidelines, ensuring compliance with standards set by authorities like JAKIM, BPJPH, and MUIS.