Vulcanisation Accelerator
Vulcanisation accelerators are chemical substances that speed and control the vulcanisation of rubber - the cross-linking of polymer chains through sulphur bridges. Without accelerators, economically viable, high-quality vulcanisation is not possible.
Three main groups are used:
1. Thiurams (e.g. TMTD, TETD): typical for latex gloves; strongest sensitisation potential
2. Dithiocarbamates (e.g. ZDBC, ZDEC): standard in nitrile gloves
3. Benzothiazoles (e.g. MBT, MBTS): in both materials
Health relevance: accelerators and their degradation products are the primary cause of Type IV contact allergies in glove users. These present as contact dermatitis with redness, itching, and blistering - typically 12-48 hours after contact.
Accelerator-free alternatives use alternative cross-linking systems: UV radiation, sulphur donors, or ionic cross-linking. These gloves can be marketed as hypoallergenic for Type IV-sensitised individuals but are more expensive to produce.
Importantly: accelerator-free does not imply latex-free, and vice versa.
Frequently asked questions
Are accelerator-free nitrile gloves truly allergy-free?
Not completely. Accelerator-free nitrile gloves contain no thiurams, carbamates, or benzothiazoles but may contain other processing auxiliaries. They significantly reduce Type IV risk but do not guarantee absolute allergy safety.
How can accelerator-free gloves be distinguished from standard nitrile gloves?
The manufacturer must explicitly state accelerator-free status on the packaging and demonstrate it in technical documentation. There is no standardised European test method or symbol for accelerator-free gloves.
Which standard governs accelerator testing for medical devices?
ISO 10993-10 governs sensitisation testing for medical devices. EN 455-3 requires biological safety evaluation for single-use gloves. No specific accelerator test standard for gloves exists - manufacturers must demonstrate compliance as part of their biological evaluation.