Overview
ISO 18642:2016 defines general requirements for fertilizer grade urea used in agriculture. The standard applies to urea in solid forms (granular, prilled, pastilled) produced from the reaction of ammonia and carbon dioxide. It sets out requirements for testing methods, sampling and preparation of test samples, marking and labelling, packaging, transport, and storage to support consistent quality and facilitate international trade of urea fertilizer.
Key topics and technical requirements
ISO 18642:2016 covers practical quality and handling requirements for fertilizer grade urea, including:
- Appearance: solid product, generally white (granular/prilled/pastill).
- Chemical and physical limits (Table 1 highlights):
- Total nitrogen (N): ≥ 45.0% (note: some regions accept 44%).
- Biuret: ≤ 1.2% (regional requirements may apply).
- Moisture (H2O): ≤ 1.0%.
- Particle size: 1.00–4.75 mm - ≥ 90% within this range (particle-size metrics such as SGN, UI, GSI may be negotiated).
- Testing methods: references specified methods for reliable analysis:
- Total N: ISO 5315 (titrimetric after distillation).
- Biuret: ISO 18643 (HPLC method).
- Moisture: EN 13466-1 (Karl Fischer).
- Particle size: ISO 8397 (test sieving).
- Sampling & sample preparation: procedures for bagged and bulk product (ISO 8633), sample reduction (ISO 7742), labelling and secure storage of laboratory samples (ISO 7410).
- Marking & labelling: comply with national/regional rules, ISO 7409, and GHS where applicable.
- Packaging, transport, storage: specify net mass per contract, protect against moisture, sunlight and damage; store in dry, cool locations.
Applications and users
ISO 18642 is practical for organizations involved in the urea fertilizer value chain:
- Manufacturers - production quality control and product specification.
- Laboratories - standardized test and sampling procedures for conformity testing.
- Traders and exporters/importers - contractual quality assurance and international trade compliance.
- Fertilizer blenders - particle-size and moisture specs for effective blending.
- Logistics and storage operators - handling and storage guidance to preserve product quality.
- Regulators and procurement teams - baseline requirements for procurement and compliance.
Keywords: ISO 18642, fertilizer grade urea, urea fertilizer, testing methods, sampling, biuret, total nitrogen, moisture content, particle size, packaging, storage, marking and labelling.
Related standards
Relevant references cited by ISO 18642 include ISO 5315, ISO 18643, ISO 8397, ISO 8633, ISO 7742, ISO 7410, ISO 7409 and EN 13466-1. These should be consulted for detailed test procedures and sampling techniques.