Work Coats & Jackets

Understanding Waterproof Ratings and Breathability

BS EN 343:2019 measures both waterproofness (Classes 1-4) and breathability of protective clothing—testing fabric, seams, zips, and pockets under real-world conditions including rain, snow, fog, and ground humidity. Waterproof ratings indicate resistance under pressure: 5,000mm provides adequate defence for most outdoor work, while 10,000mm+ offers excellent protection against heavy rain and wet snow. Here's what many buyers miss: fabric waterproofing means nothing without sealed construction. Check for taped seams and waterproof zips.

Breathability ratings (measured in grams per square metre over 24 hours) determine how well moisture vapour from perspiration escapes. For physically demanding work, you need 15,000-20,000g/m² minimum. Without adequate breathability, sweat accumulates inside the coat, soaking your base layers and dramatically increasing heat loss—exactly what waterproofing is meant to prevent.

Insulation Types and Weight Selection

Synthetic insulation continues working when wet, dries quickly, and typically costs less than down. It's rated in grams per square metre: • 100-200g provides moderate warmth for active tasks like groundwork or utilities maintenance • 200-400g offers heavier insulation for static work or temperatures below freezing. Down insulation delivers superior warmth-to-weight ratios but loses all effectiveness when damp—impractical for UK outdoor work where rain falls 148 days per year (40% of the time).

Common mistake: overspecifying insulation weight. If you're moving throughout your shift, excessive insulation causes overheating and sweat buildup. Match insulation to activity level, not just temperature.

Why Core Temperature Protection Matters

Your torso contains vital organs and major blood vessels that distribute warmth throughout your body. When core temperature drops below 35°C, hypothermia begins—symptoms include shivering, confusion, slurred speech, and loss of consciousness. Maintaining torso warmth ensures your cardiovascular system keeps healthy circulation to hands and feet, reducing cold-related injuries and frostbite risk. This is why a quality winter work coat provides better overall protection than multiple lighter layers, though combining a good coat with appropriate base and mid-layers offers optimal performance in severe conditions.

Wind chill accelerates heat loss significantly. Employers evaluating cold weather risks must account for wind chill when determining worker protections under UK PPE regulations—and that starts with proper torso insulation.