Knowledge hub
Articles from the Molekula editorial team
Coverage of chemistry, regulatory updates, methods, supply-chain insight, and product spotlights. New articles published daily.
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Method
Diluting Concentrated Stocks: C1V1 = C2V2 and Serial Dilutions
To dilute concentrated stocks accurately, use the formula C1V1 = C2V2, where C1 and V1 are the initial concentration and volume, and C2 and V2 are the final concentration and volume. For serial dilutions, apply the formula iteratively across multiple steps, ensuring consistent dilution factors. Precision depends on calibrated equipment and correct technique.
Jun 3, 2026 · 4 min read -
Method
Calculating Molarity: Mass, Molecular Weight, Volume and Common Pitfalls
Molarity (mol/L) is calculated using mass (g), molecular weight (g/mol), and volume (L). The formula is M = (mass / MW) / volume. Common errors include incorrect unit conversion, ignoring solute hydration, and inaccurate volume measurement. Always verify units and use calibrated equipment.
Jun 2, 2026 · 4 min read -
Supplier-news
Understanding HTS and Tariff Codes for Chemical Imports: A Guide for UK and EU-Based Researchers
Customs Harmonised Tariff Schedule (HTS) codes are essential for classifying chemical imports under UK and EU trade regulations. Accurate HTS codes ensure compliance with REACH, TSCA, and GHS, and prevent delays or penalties. Codes vary by chemical structure, purity, and intended use. Always verify with national customs authorities or a qualified customs broker.
Jun 1, 2026 · 5 min read -
Regulatory
IATA/ADR Transport Classifications for Laboratory Chemicals
Laboratory chemicals are subject to IATA (air) and ADR (road) regulations based on hazard classification. Key categories include flammable liquids (Class 3), corrosives (Class 8), and toxic substances (Class 6.1). Proper classification requires evaluation of flash point, toxicity (LD50), and reactivity. Labels, packaging, and documentation must comply with UN recommendations and regulatory standards.
May 31, 2026 · 4 min read -
Regulatory
Cold-chain shipping regulations for biological reagents
Biological reagents must be shipped under controlled temperature conditions to maintain stability and integrity. Regulations vary by region, with EU and US frameworks requiring compliance with ISO 11607, REACH, and TSCA. Temperature monitoring via validated data loggers and adherence to GHS labelling are mandatory. Shipping durations and storage conditions depend on the reagent type and stability data.
May 30, 2026 · 5 min read -
Applications
Pharmacopoeia Grades (USP/EP/BP): What They Mean for Procurement
Pharmacopoeia grades (USP, EP, BP) denote substances meeting strict quality, purity, and testing standards for pharmaceutical use. Procurement teams must verify compliance with relevant monographs, ensure traceable CoA and SDS, and confirm batch consistency. These grades are essential for regulatory submissions and clinical trial material sourcing.
May 29, 2026 · 4 min read -
Method
CAS Registry Numbers Explained: How to Find the Right One
CAS registry numbers are unique identifiers for chemical substances, essential for accurate sourcing and regulatory compliance. Each number is assigned by the Chemical Abstracts Service and consists of up to 10 digits separated by hyphens. Use official databases like CAS SciFinder or Reaxys to verify and locate the correct number for a given compound.
May 28, 2026 · 4 min read -
Regulatory
GHS Pictograms and Hazard Statements: A Buyer's Guide for Chemists and Biotech Teams
GHS pictograms and hazard statements are standardised across global chemical regulations to communicate hazards clearly. This guide explains their structure, interpretation, and compliance requirements under REACH, TSCA, and GHS, with reference to specific hazard classes and signal words.
May 27, 2026 · 5 min read -
Regulatory
TSCA Inventory: What U.S. Importers Should Know
The U.S. Toxic Substances Control Act (TSCA) inventory lists chemicals manufactured or imported into the United States. Importers must verify a chemical’s presence on the TSCA Inventory before importing. As of 2023, the inventory includes over 86,000 chemicals. Non-inventory chemicals require pre-manufacture notification (PMN) under TSCA §5. Compliance is enforced by the U.S. Environmental Protection Agency (EPA).
May 26, 2026 · 4 min read -
Regulatory
REACH Compliance for Chemical Suppliers: Key Requirements and Deadlines for 2026
All chemical suppliers operating in the EU must comply with REACH regulations by 2026. Key obligations include registration of substances above 1 tonne per year, submission of safety data, and adherence to authorisation and restriction requirements. Non-compliance risks market access and legal penalties.
May 25, 2026 · 4 min read