A package of SEALING COMPOUND SLUGS, a flexible and moldable sealing material.

Sealing Compound Slugs SCS-1

SEALING COMPOUND SLUGS is the instant, professional-grade solution for sealing out air, dust, and moisture in HVAC/R, plumbing, and general maintenance. This is a highly specialized, non-staining sealer that is brick-shaped so that it can be made to fit anywhere for mess-free, thumb-applied installation. Formulated from the highest quality raw materials, the compound remains flexible across extreme temperatures, ensuring a durable, permanent seal that won’t harden, shrink, or pull away over time.

SKU: SCS-1 Category: INSULATION Tags: air-proof, Brick, Dust Resistant, Flexible Sealant, HVAC Sealant, non-hardening., SCS-1, sealant, sealing compound, Sealing Compound Slugs, Thumb Gum, Water Resistant, water-proof, weatherproofing Brand: Vapco Products

SEALING COMPOUND SLUGS

Versatile and Durable Sealing Solution

SEALING COMPOUND SLUGS (SCS-1) is the ultimate self-adhesive, pliable sealant designed for all-purpose sealing, insulation, and maintenance applications in HVAC/R, automotive, industrial, and construction sectors. This premium, white, non-staining compound is supplied in two convenient, 1-pound bars (slugs) per box, offering a bulk, moldable material that can be worked by hand into any desired shape. The slug format is ideal for filling larger voids, irregular openings, and gaps where traditional cords or tapes are inefficient. The compound’s specialized formulation provides exceptional temperature stability, remaining fully flexible down to $-20^\circ\text{F}$ and exhibits no sag up to 350°F. This ensures a permanent, reliable seal that is water and vapor proof, yet remains soft, flexible, and will not harden, shrink, or crack over time.

Key Features and Benefits:

Effective Sealing: Protects against air, dust, and moisture in hot and cold settings.
Versatile Applications: Suitable for sealing windows, air ducts, adaptors, and extensions.
No Tools Required: Easy to apply with fingers/thumbs.
Non-Hardening and Non-Staining: Maintains flexibility and appearance between -20°F and 350°F.
Odorless and Non-Corrosive: Safe for use in various environments.
Adheres to Most Surfaces: Compatible with metal, plastics, glass, and wood.

Ideal Applications:

HVAC: Seal window openings, air ducts, adaptors, extensions, small voids etc. to prevent energy-waisting air leaks. Seal out air, dust, moisture.
Refrigeration: Seal out air and moisture around tube entries/exits, under latch plates, under hinges, and over screw heads in refrigeration units and freezers.
General Maintenance: Plug holes, cracks, and small voids, seal long gaps; and provide non-staining sealing where the compound needs to be painted.

Part Number; Size

SCS-1 2 lb 24/cs

Directions:

Prepare Surface: Ensure the surface is clean and dry.
Removal: Slugs are in an easy moldable brick format that can be worked by hand into any shape or irregular opening.
Apply Sealant: Place the SEALING COMPOUND SLUGS on the area to be sealed.
Press into Place: Use your thumbs to firmly press the sealant into place. Ensure it is pressed sufficiently to fill the opening and achieve solid adhesion to the surrounding area.

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SDS

⚠️ SEALING COMPOUND SLUGS SDS – DOWNLOAD

1. Identification & Supplier Details

Product Name	Sealing Compound Slugs
Product Number	SCS-1
Brand	Vapco
Recommended Use	For use as a seal against water, dust and air. Can also be used as a noise and sound deadener.
Supplier	Vapco Products, Inc. 401 Marshall Road, Valley Park, Missouri 63088, United States
Telephone / Fax	(636) 923-2121 / (636) 923-3002
Emergency Phone	(800) 255-3924 (ChemTel)

2. Hazard Identification & Composition

GHS Classification	Carcinogenicity (Cat. 1A); Eye damage/irritation (Cat. 2B); STOT RE (Cat. 2); STOT SE (Cat. 1)
Signal Word	DANGER
Hazard Statements	H320: Causes eye irritation H350: May cause cancer via inhalation of dust H370: Causes damage to organs [lungs/respiratory system] through inhalation H373: May cause damage to organs [lungs] through prolonged or repeated exposure

Hazardous Components	CAS No.	Concentration
Limestone	1317-65-3	70 – 80 %
1-Propene, 2-methyl-, homopolymer	9003-27-4	10 – 20 %
Talc (no asbestos fibres)	14807-96-6	1 – 10 %
Chlorite-group minerals	1318-59-8	1 – 5 %
Quartz (respirable dust)	14808-60-7	< 1 %

3. Physical & Chemical Properties

Physical State & Appearance	Putty-like solid; Off-white
Odor	Faint, mild odor
Density	1.81 g/cm3
Decomposition Temp	>200°C (392°F)
Solubility	N/D
Flammability	Not classified as a flammable hazard

4. Stability & Reactivity

Reactivity	Not reactive.
Chemical Stability	Stable under normal conditions of storage and use.
Conditions to Avoid	None known.
Incompatible Materials	Avoid contact with strong oxidizers.
Hazardous Decomposition	Carbon oxide(s), isobutene and other combustion products are possible.

5. Toxicological Information

Acute Toxicity	Limestone: LD50 Oral – 6450 mg/kg Butene, homopolymer: LD50 Oral – >5000 mg/kg; LD50 Dermal – >3000 mg/kg Crystalline silica: LD50 Oral – 500 mg/kg
Carcinogenicity	Contains >0.1% crystalline silica; listed as a Group 1 carcinogen by IARC and known carcinogen by NTP/OSHA.
Eye/Skin Effects	Causes eye irritation. May cause skin irritation through prolonged exposure.
Target Organs	Damage to lungs and respiratory system via inhalation.

6. First-Aid Measures

Inhalation	Remove to fresh air. Keep at rest in a position comfortable for breathing. Seek medical attention.
Skin Contact	Drench with water for 15 minutes. Remove contaminated clothing. Obtain medical attention if irritation persists.
Eye Contact	Rinse with water for at least 15 minutes. Remove contact lenses. Obtain medical attention.
Ingestion	Rinse mouth. Do NOT induce vomiting. Obtain medical attention.

7. Fire-Fighting & Accidental Release Measures

Extinguishing Media	Water spray, fog, CO2, alcohol-resistant foam, dry chemical, or sand.
Firefighting Hazards	Hazardous combustion products include Carbon oxide(s) and isobutene. Wear NIOSH-approved SCBA.
Spill Procedures	Evacuate unnecessary personnel. Eliminate ignition sources. Contain with dikes or absorbents. Prevent entry to sewers.

8. Handling, Storage & PPE

Safe Handling	Avoid contact with skin, eyes, and clothing. Do not breathe dust or vapors. Wash hands thoroughly after handling.
Storage Conditions	Store in a dry, cool, well-ventilated place away from ignition sources and direct sunlight. Keep container locked up.
PPE – Eyes/Body	Chemical safety goggles; protective gloves; fire/flame resistant clothing.
PPE – Respiratory	Use NIOSH-approved SCBA whenever exposure may exceed established Occupational Exposure Limits.

9. Transport & Regulatory Information

DOT / IMDG / IATA	Not dangerous goods
CA Prop 65	WARNING: This product can expose you to crystalline silica, known to the State of California to cause cancer.
Right to Know (NJ/PA/MA)	Listed: Limestone (1317-65-3), Talc (14807-96-6), Quartz (14808-60-7).
TSCA Inventory	All components are listed on the US EPA TSCA public inventory.

10. Disposal & Ecological Information

Ecological Toxicity	No data available. Does not contain Montreal Protocol ozone-depleting substances (>0.1%).
Product Disposal	Does not meet RCRA hazardous waste criteria in purchased form. Do not dispose into storm water or sewage systems.
Packaging Disposal	Dispose of in accordance with local regulations. Recycled at approved waste handling sites.

11. Disclaimer & Preparation Information

Disclaimer	Information is accurate to the best of our knowledge. No warranty, expressed or implied, is created. User is responsible for suitability and compliance with regulations.
Prepared By	Jessica Wilson
Date Prepared	January 12, 2026

Sealing Compound Slugs SCS-1

SEALING COMPOUND SLUGS