Dichloromethane, also known as Methylene Chloride, is a halogenated hydrocarbon and an organic chlorine compound used in peptide synthesis for washing, deprotection, and splitting purposes. It has a Molecular Weight of 84.93 g/mol and a Boiling Point of 103.6°F at 760 mmHg (NTP, 1992). This substance requires safety precautions such as wearing protective gloves and goggles due to potential skin irritation and hazards associated with ingestion. The recommended indicative occupational exposure limit value for the European Union is 8 hours limit value: 353 mg/m3 (100 ppm), and short term limit value: 706 mg/m3 (200 ppm), with a risk of percutaneous absorption.

• CAS Number: 75-09-2
• Molecular Formula: CH2Cl2
• Molecular Weight: 84.93
• Exact Mass: 83.9533555
• Boiling Point: 103.6 °F at 760 mmHg (NTP, 1992)
• Melting Point: -142.1 °F (NTP, 1992)
• Vapour Density: 2.93 (NTP, 1992) - Heavier than air; will sink (Relative to Air)
• GHS Signal Word: Warning
• Hazard Statements:
• H351: Suspected of causing cancer [Warning Carcinogenicity]
• H302 (24.1%): Harmful if swallowed [Warning Acute toxicity, oral]
• H315: Causes skin irritation [Warning Skin corrosion/irritation]