ATH vs MDH: The Flame Retardant Showdown

Both Aluminum Hydroxide (ATH) and Magnesium Hydroxide (MDH) are the workhorses of halogen-free flame retardancy. If you're manufacturing cables, building materials, or automotive parts in India, you've likely debated which one to use.

Here's the no-nonsense comparison.

The Core Difference: It's All About Temperature

The single most important differentiator is decomposition temperature:

The rule is simple: if your processing temperature exceeds 220°C, ATH will decompose during extrusion. You need MDH.

Indian Market Pricing

ATH is 30-40% cheaper than MDH. At production volumes of 10+ tons/month, that's a significant cost difference.

When to Use ATH

• PVC cable compounds — processing at ~170-190°C, ATH is perfect
• Rubber compounds — natural and synthetic rubber processing
• Thermoset composites — SMC, BMC, hand lay-up
• Conveyor belts — mining and industrial
• Budget-sensitive applications — when cost drives the decision

When to Use MDH

• PE and PP cables — HFFR/LSZH compounds need MDH's higher thermal stability
• EVA compounds — solar panel encapsulants, shoe soles
• Engineering thermoplastics — PA, PBT applications
• Automotive under-hood — high heat exposure environments
• UL94 V-0 at lower loading — MDH can be more efficient

Loading Levels: The Trade-Off

Both require 40-65% loading by weight. This hits your mechanical properties hard:

• Tensile strength drops 30-50%
• Elongation reduces significantly
• Surface finish can become rough

Pro tip: Use surface-treated grades (silane or stearate coated) to improve dispersion and maintain better mechanicals.

The Verdict

Always request samples from 2-3 vendors and test in your actual formulation before committing to production volumes.