Number
448-EN
Section
General Section
Use
Sector
Manufacture of plastics products, including compounding and conversion
Building and construction work
Function
Monomers
Process
Transfer of substance or mixture (charging and discharging) at dedicated facilities
Other
Product category
polymer ppaations and cimpounds
Application
Production of parts by injecting mold of resins. Styrene is used as a monomer.
Abstract
Company produces parts for various articles (e. g. sofas, ship hulls, etc.) with resin molding. Resin, which contains volatile styrene, is molded onto glass, carbon or other fiber fabric to form the stable parts. This is done manually.
Styrene is suspected to be toxic to reproduction, causes damage through prolonged or repeated exposure, and harmful if inhaled.
The company automated the process by installing resin transfer molding (RTM) equipment. This significantly reduced VOC (styrene) use, emissions, and exposure from polystyrene resin molding.
Substituted substances
Styrene
CAS No. 100-42-5 EC No. 202-851-5 Index No. 601-026-00-0
Chemical group
Aromatic hydrocarbons
Classification: hazard statements
H226 Flammable liquid and vapour
H361d Suspected of damaging the unborn child
H332 Harmful if inhaled
H372 Causes damage to organs through prolonged or repeated exposure
H315 Causes skin irritation
H319 Causes serious eye irritation
Other adverse effects
The substance is: 2B carcinogen (IARC), endocrine disruptor (SIN List), endocrine disruptor cat. 1 (EU EDC database), as listed in the Substance Database according to SUBSPORT Screening Criteria (SDSC).
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
other reasons
Hazard Assessment
Substances to be substituted:
Styrene is suspected to be reproduction toxic according to harmonized classification (H361d). It is also harmonised classified for other toxic properties.
Other adverse effect according to SDSC-list: EC endocrine disruptors database cat. 1, SIN list: endocrine disruptor (https://sinsearch.chemsec.org/chemical/100-42-5)
Alternative substances:
not applicable here
Description of Substitution
a) Motivation to apply the alternative
The motivation for the company to improve the situation was driven by a wish to reduce VOCs in the workplace and to be more efficient (faster production, less defective products, etc.).
b) Description of procedure or technology (including pre-/post-processing)
Resin transfer molding (RTM) is a liquid injection molding process that utilizes liquid resin injection under pressure through a dry fiber preform placed in a closed mold cavity. The resin the company used in RTM is a polystyrene mixture, premixed with the hardener. As the uncured liquid resin flows and spreads throughout the mold, it fills the space between the fibers, displaces the entrapped air through the air vents in the mold and coats the fibers. After the cured part is pulled out of the mold, it may sometimes be necessary to trim the part at the outer edges to achieve the final dimensions.
Before installing RTM equipment, the company mixed and applied resin on composite materials manually and then closed the mold with plastic sheet material, sealed it and then evacuated air from the space between the sheet and the layup using a vacuum pump.
c) Way of application: e.g. spraying, dipping, open/closed system etc.
Injection under pressure; closed system.
d) Risk management measures (technical, organizational and personal)
Styrene evaporation is almost eliminated using RTM equipment. Due to lower VOC emissions, and the use of PPE is reduced (no need to use activated carbon respirator).
e) Advantage or Disadvantage of alternative
Technical requirements: Better mechnical properties
Implementation: Investment costs of about 20.000 EUR
Further Advantages:
- Significant decrease of evaporation of styrene while dosing and mixing the ingredients;
- Dosing is optimized;
- Less pollution of production bar, mixing tools;
- Waste reduced (by 10% per product) due to better quality of built parts (e.g. less polishing is needed);
- Work procedures are easier, process is simpler and quicker (approx. 3 times quicker);
- Working time and labor costs should lower by 15-20%;
- Lower VOC emissions, thus lower occupational safety costs, reduced use of PPE (no need to use activated carbon respirator).
Case/substitution evaluation
Mixtures used still contain styrene but the percentage of styrene is lower by approximately 10%.
The technical alternative reduces the emission of styrol, which is difficult to replace, thereby increasing safety at the workplace. There are no substances alternatives for styrol at the moment, so that safe handling recommendations and technical solution play an important role.
State of implementation
In use
Availability ofAlternative
The alternatives are available on the market.
Producer/Provider
https://wolfangel.com/en/rtm-systems/ (the one company has purchased) Others: Applicator group AB, GlassCraft UK
Type of information supplier
User
Contact
LIFE Fit For REACH project, www.fitreach.eu
Further information
Factsheet: Construction company reduces use and emission of styrene after automatisation of process
Publication source: author, company, institute, year
if available
Date, reviewed
March 1, 2013