Number
294-EN
Section
General Section
Use
Sector
Building and construction work
Manufacture of rubber products
Manufacture of plastics products, including compounding and conversion
Function
Stabilizing agent
Process
Other
Product category
polymer ppaations and cimpounds
Application
Environmentally friendly PVC-Stabilisation
Abstract
Polyvinyl chloride (PVC) is one of the most important commercial plastic materials, but it is thermally unstable at a processing temperature. Processing of PVC at elevated temperatures requires the use of thermal stabilisers. Widely used thermal stabilisers for PVC incorporate toxic heavy metals like lead or cadmium and another organotin compounds that have been severely criticised based for human health and environmental concerns. In order to address this issue, hydrotalcites that are compatible with the polymer had been investigated.
Substituted substances
Lead, metal
CAS No. 7439-92-1 EC No. 231-100-4 Index No.
Chemical group
Metals
Classification: hazard statements
H360FD May damage fertility. May damage the unborn child
H362 May cause harm to breast-fed children
Other adverse effects
The substance is: 2B carcinogen (IARC), neurotoxic cat. 4 (Vela et al.) as listed in the Substance Database according to SUBSPORT Screening Criteria (SDSC).
Cadmium
CAS No. 7440-43-9 EC No. 231-152-8 Index No. 048-002-00-0
Chemical group
Metals
Classification: hazard statements
H250 Catches fire spontaneously if exposed to air
H350 May cause cancer
H341 Suspected of causing genetic defects
H361fd Suspected of damaging fertility. Suspected of damaging the unborn child
H330 Fatal if inhaled
H372 Causes damage to organs through prolonged or repeated exposure
H400 Very toxic to aquatic life
H410 Very toxic to aquatic life with long lasting effects
Other adverse effects
The substance is: 1 carcinogen (IARC) as listed in the Substance Database according to SUBSPORT Screening Criteria (SDSC).
Alternative Substances
Hydrotalcite, synthetic
CAS No. 11097-59-9 EC No. 234-319-3 Index No.
Chemical group
Carbonates
Reliability of information
Evidence of implementation: there is evidence that the solution was implemented and in use at time of publication
Reason substitution
CMR
other toxic effects
ecotoxicity
Hazard Assessment
Substances to be substituted: Lead is a Substance of very high concern and is included on the REACH restriction list, according to Article 73 of Regulation (EG) No. 1907/2006. (REACH Regulation). Cadmium is a Substance of very high concern and is included on the REACH restriction list, according to Article 73 of Regulation (EG) No. 1907/2006. (REACH Regulation). Alternative substance: The alternative stabiliser has no official classification and is not listed in SDSC.
Description of Substitution
PVC is expected to remain important among thermoplastics because of its compatibility with a large number of other products (e. g. plasticisers, impact modifiers), in contrast to other plastics. Because PVC’s mechanical properties can be adjusted over a wide range, yielding everything from rigid to flexible end products, there are many different processing methods for PVC. Vinyl products are commonly used, including toys, car interiors, shower curtains, and flooring and mainly release chemical gases into the air. PVC is divided into soft (plasticised) and hard (unplasticised). Risk assessments have led to the classification of low molecular weight PVC (soft) and labelling as category 1B reproductive agents. Hydrotalcite is a double-layered inorganic complex. In its natural form, it is hydrated magnesium-aluminium hydroxycarbonate with the formula: Mg6Al2 (OH)16CO3 x 4H2O, which can be commercially produced. This chemical is derived hydrotalcite from the magnesium hydroxide (brucite). Hydrotalcite is confirmed to be environmentally safe and effective co-stabilisers for rigid PVC: static thermal stability (through oven testing) and dynamic thermal stability (via torque rheometry). PVC compounds are modified by their presence. The extent of change is determined by the primary stabiliser type and the grade of the hydrotalcite.
Case/substitution evaluation
This case story described the replacement of the carcinogens PVC- stabiliser with a safe alternative. During stabiliser substitution the health and safety in the production and processing of PVC can be improved. The lead stabiliser systems were reduced dramatically from 145,000 t to 2000 in the European Union (EU17) from 100,000 t to 2007 (EU 25) and should be substituted completely by 2015 by lead-free stabiliser systems. According to Annex XVII of the REACH Regulation, PVC products may no longer be placed on the market if the lead concentration is ≥ 0.1 mass percent of the PVC material.
State of implementation
In use
Date and place of implementation
2000 in Germany
Availability ofAlternative
on the market
Producer/Provider
See: Contact: Information supplier
Type of information supplier
Research
Contact
Süd-Chemie AG https://www.clariant.com
Type of publication and availability
A free available article
Publication source: author, company, institute, year
Wernicke H. J., Großman J. (2009) Stabilisierung von PVC durch synthetische Hadrotalcite Umweltfreundliche Schichten. HighChem hautnah - Aktuelles zur Nachhaltigen Chemie. Gesellschaft DEer Chemiker
Publication source
Type of publication and availability
http://archiv.aktuelle-wochenschau.de/2008/woche43/woche43.html
Date, reviewed
November 26, 2021