Part III POPs-free/POPs alternatives – overview and case studies
Alternative to HBCD
Alternatives to HBCD
HBCD is used as a flame retardant in a variety of materials, such as a flame retardant in expanded polystyrene foam (EPS) and extruded polystyrene foam (XPS) as well as textiles and in high-impact polystyrene (HIPS) in electronics housings. The major use is in EPS and XPS used as rigid foam insulation in the building and construction industry.
Case study: Alternative HBCD EPS insulation materials in construction
The study identified alternative insulation materials marketed for all applications of flame retarded EPS in buildings.
The study focused on two main aspects: identification of alternatives to flame retarded EPS and a comparison with the alternative materials selected.
Among the alternative materials identify it can mention the followings:
a)Stone wool (representing mineral wool materials), which is marketed for the same application areas as flame retarded EPS although some minor changes in the construction may be required;
b)The PUR/PIR foams (representing plastic foams), which can substitute for flame retarded EPS for nearly all applications;
c)Wood fibre boards (representing natural fibre-based insulation), which may be used for some of the same applications as flame retarded EPS, although the material’s vulnerability to moisture may restrict its uses for some applications;
d)Cellular glass, which has a very high resistance to compression compared to EPS and can reduce dimensions of a load bearing insulated walls in some cases.
The comparison with alternative materials was made against the following criteria: technical feasibility, fire safety, human health and ecotoxicological impact, other environmental impacts and resource consumption, recyclability and price of material.
The study concluded that alternatives are available for all the applications of flame retarded EPS assessed. It is anticipated that the flame retarded EPS would be replaced by different insulation materials depending on the application, as no alternative assessed would substitute for all EPS applications, if the use of flame retarded EPS is restricted. Also - and most importantly - that the alternatives typically have better fire performance and contain less problematic chemical substances.
Prices of the cheapest alternatives ranged from approximate equivalence to flame retarded EPS to approximately 30% more. There are also alternatives with significantly higher prices, but these are typically used because they have some desired technical advantages and would, probably not be the first choice substitutes for general application. For some applications, where flame resistance is not needed, non-flame retarded EPS would probably take over, to the extent national regulation allows.
COVI (2011), Chemicals in products. Alternatives to the use of flame retarded EPS in buildings.
The alternatives assessment considered two alternatives to HBCD. One of the alternatives, a butadiene styrene brominated copolymer, is a polymer with a molecular weight (MW) much greater than 10,000 daltons. The other, a tetrabromobisphenol A (TBBPA)-bis brominated ether derivative, is a large molecule with a MW close to 1,000 daltons. Both of these chemicals incorporate bromine as the mechanism for fire retardation. The limited number of alternatives is, at least in part, due to the requirement that flame retardants for expanded polystyrene (EPS) and extruded polystyrene (XPS) foam
(1) allow the material to comply with fire safety codes,
(2) not compromise the physical properties of the foam, and
(3) be compatible with its manufacturing processes and formulas.
These alternatives were evaluated against the following criteria: (1) human health hazard, (2) ecotoxicity, (3) persistence, (4) bioaccumulation potential, and (5) exposure potential.
When selecting alternative insulation materials, there are several insulation characteristics that should be considered, such as environmental considerations, material safety considerations, performance considerations, and economic considerations.
Material substitution of EPS/XPS foam
Rigid Board Alternatives
The alternative insulation materials identified are available as rigid board and therefore can be used in many of the same applications as EPS and XPS. The materials readily available as board insulation include polyisocyanurate foams, perlite insulation, and mineral wool/rockwool insulation.
Alternatives for Certain Functional Uses
The alternative insulation materials which may be used for certain functional uses of EPS and XPS are generally not available as rigid board insulation, but may be used in certain applications where the properties such as dimensional stability or compressive strength are not integral to the performance of the insulation material. Alternative insulation materials that may be used for certain functional uses of EPS and XPS are: cellulose, cementations foam, cotton insulation, fiberglass and polyurethane.
Specialty and Emerging Alternative Materials
There are also insulation materials that may be functional alternatives to EPS and XPS, but are not considered to be currently viable for large scale building applications, and so are constrained to specialty applications or limited geographic areas. This information is intended to provide context in case changes in manufacturing processes or economies of scale allow these products to become viable in the future. Speciality and emerging alternative insulation materials identified include: aerogel, carbon foam, foamglas, phenolic foam, reflective insulation and agrifiber insulation.
Case study from SUBSPORT: Specific substance alternative assessment HBCD
The study concluded that alternative chemical substances and materials have been identified for the major HBCD use in EPS and XPS insulation foams, in HIPS and in textile back coating applications.
With the exception of triphenyl phosphate for HIPS application, the substances that were considered in this alternatives assessment all passed the Substance Database according to SUBSPORT Screening Criteria (SDSC).
The chemicals and material alternatives identified for EPS and XPS, HIPS and textiles back coating applications are judged to be technically feasible and commercially available. They can therefore be assumed to be economically feasible as the material alternatives, particularly, are currently in use in some countries in Europe. Non-flame retarded EPS and XPS with thermal barriers are used in countries where regulation does not specify the use of flame retarded EPS and XPS insulation foams without any reduction in the fire safety performance of construction and rock wool is marketed for most applications where EPS is traditionally used. Alloys of PPE/HIPS treated with halogen-free flame retardant are used by major European TV set manufacturers.
From a safety perspective, no definite safer alternatives for the various HBCD applications were identified. Some of the chemical and material alternatives are associated with hazard characteristics of concern. Other alternatives lack data to allow for a final assessment of their hazards.
However, according to the Risk Management Evaluation for HBCD prepared by the POPRC, the current building practice from Sweden and Norway, where most of the EPS and XPS used is HBCD-free, suggests that fire-safety of building materials and buildings can be obtained at a reasonable cost without the use of HBCD and without altering traditional building and construction techniques to a great extent. According to an analysis on alternatives to flame retardant EPS made in Norway, a change from flame retarded EPS to the alternative insulation materials would consequently not compromise fire safety and the alternatives would in general be able to meet the same requirements, or higher, as the flame retarded EPS. The alternatives, including non-flame retarded EPS in combination with thermal barriers, typically have better fire performance and can compete with regard to the insulation properties and moisture resistance required in most applications in both cold and warm climates. According to Climate and Pollution Agency in Norway (KLIF) the price of the cheapest alternatives ranges from more or less the same price as for flame retarded EPS to approximately 30 % more.
There is limited data available to assess the life cycle impacts of the alternative chemical substances and materials. Only non-flame retarded EPS and XPS with thermal barriers and rock wool which are both material alternatives for HBCD in flame retarded EPS and XPS insulation foams application have some information describing their respective life cycle impacts.
 The Substance Database according to SUBSPORT Screening Criteria (SDSC) contains substances that are known to be carcinogens, mutagens or toxic for reproduction – CMR, (very) persistent, (very) bioaccumulative or toxic – (v)P(v)BT, endocrine disruptors, neurotoxicants or sensitization agents taken from the following sources:
CMR: CLP Regulation cat. 1A, 1B (Dir. 67/548, categ. 1 and 2); IARC group 1, 2A, 2B
Sensitization agents: CLP Regulation for H334, H317 (Dir. 67/548, for R42, R43).
 UNEP (2011), Risk management evaluation on hexabromocyclododecane. UNEP/POPS/POPRC.7/19/Add.1.
 Climate and Pollution Agency in Norway (2011). Alternatives to the use of flame retarded EPS in buildings. A report by COWI AS Denmark. Authors: Lasses C, Maag J, Hoibye L, Vesterlykke M, Lundegaard T. 97 p.