Optimization of PVC-free materials in cables

Appendix 10
Environmental aspects of selected compounds for cable production

Prepared by
Jørgen Larsen

Danish Technological Institute
Centre of Environmental Technology
June 1996

Table of Contents

1. Introduction

2. Summary of the report

3. Method
3.1 Eco-profiles
3.1.1 Description of the elements used to assess the health and environmental impacts of the selected compounds.
3.2 Presentation of the results

4. Assessment of the selected compounds
4.1 Summary/remarks of the assessment of NKT's PVC
4.2 Summary/remarks of the assessment of the HFFR compounds

5. Conclusion/comparison

Reference

1. Introduction

This report is a study of the environmental and health aspects related to different plastics used as materials for cable production. DRAKA/NKT has during the last couple of years performed extensive investigations of selected HFFR compounds on the market. Since the aim of this work is to improve the environment by substituting PVC used for cable production with HFFR compounds the Danish Technological Institute, Department of Environmental Technology, has performed a toxicological (health aspects) and eco-toxicological assessment (effects on the external environment) of the 3 finally selected HFFR compounds

and made a comparison of the selected compounds to the NKT's PVC compound no. 5313 presently used for cable production.

In the evaluation of the materials, an eco-profile has been made for each material. The aim of these eco-profiles is to provide clear and transparent information on the potential impacts of the material on health /environment and to identify if any problematic elements ("the fingerprint") of that particular material are present.

During the preparation of an eco-profile report, it is absolutely necessary to know the exact composition of the product. All firms involved have provided the exact composition details of their products to the consultants which makes it possible to prepare four eco-profile reports, one for each of the products (the 3 selected HFFR compounds and the NKT's PVC). As the exact composition details of these products are highly confidential it is not possible to publish the information in this report. Therefore, the report only includes a short summary of the main conclusions and not the exact information about e.g. the consumption of energy and raw materials for the production of the different materials (the information can only be found in the eco-profile reports prepared for each material). Thus, the present report is only a part of a larger reporting complex on "integrated environmental and occupational assessment of selected plastics used in connection with cable production.

2. Summary of the report

The report describes the accumulated results of a toxicological and eco-toxicological evaluation of the chemical ingredients in each material.

The results from the evaluation of the different compounds are presented in both a specific matrix where the focus is on the material and in a relative matrix where the compounds are compared to PVC.

HFFR compounds The results from the 3 eco-profile reports emphasized that no significant differences exist between the 3 selected HFFR compounds, neither from a toxicological nor eco-toxicological point of view. In this summary report, the presentation of the 3 HFFR compounds is therefore treated as one.

The specific matrix shows that the problematic elements ("the fingerprints") of the selected LSOH compounds are primarily in the production phase. The process takes place at an elevated temperature and pressure and there is thus a risk of run-away reaction with a danger of fires and explosions.

The breakdown products, when processing the material, comprise a number of acids, ketones and aldehydes with a potential for airway irritation in humans. The coupling agents might be of some concern in the work environment during compounding and manufacturing of products.

From a environmental point of view, carbon oxides, sulphur oxides, nitrogen oxides, and hydrocarbons are the important air emissions. Waste water from the polymerization will have a high BOD value and should therefore be treated before discharge to the recipient.

The energy consumption in the production of the selected HFFR compounds will differ according to the particular material but will in all circumstances be larger than for NKT's PVC no. 5313.

The material is only of minor concern in normal use.

When deposited on landfill, HFFR compounds are very slowly degraded, if degraded at all. HFFR compounds do not give rise to any serious problems in waste incineration.

NKT's PVC no. 5313 From a health and environmental point of view, the problematic elements ("the fingerprints") in the life cycle of NKT's PVC no. 5313 are primarily in the production process (including the compounding and processing) and waste management. However, PVC may also constitute a problem during use in connection with unintentional fires.

Emissions of VCM (vinyl chloride monomer), EDC (ethylene dichloride) and dioxines are the most important substances to control in the production (during production of raw materials and polymerization), due to their potential large emissions and their health effects. From an environmental point of view, it is furthermore important to control releases of all chlorinated substances, including dioxines.

The plasticizers might perhaps be of some concern in the work environment during compounding and manufacturing of products.

The material is only of minor concern in normal use. PVC does not burn by itself and has a comparatively high self ignition temperature. However, if other materials support a fire PVC will burn under the formation of e.g. carbon oxides and hydrochloric acid fumes and the soot formed at the fire may contain traces of dioxines, the amount depends on the fire conditions.

It is questioned for the time being whether it is feasible to recycle PVC containing lead from old cables because it keeps lead in circulation in society instead of phasing it out.

When deposited on landfill, PVC is very slowly degraded, if degraded at all. PVC plasticizer may leach out of the product and could be a source to emissions to soil and water.

By the incineration of PVC, hydrochloric acid is formed. Because of the environmental effects of the acidic fumes the stack gasses are normally neutralized by the use of large amounts of lime. Dioxines may occur, however, the amount depends on the fire conditions.

The residues from the cleaning of stack fumes from incineration of cable waste contain metals and traces of dioxines.

Relative matrix Even through the energy consumption during production of raw materials of the HFFR are larger than for the PVC material, the HFFR compounds must be considered as an environmentally friendly alternative to PVC. This judgement is primarily based on the fact that no potential for exposure and effects of carcinogenic substances during production and lower amounts of acidic fumes and dioxines are formed by waste disposal. Furthermore, there is no need for addition of plasticizers like e.g. phthalates often used in products made of PVC. The material is only of minor concern in normal use, however, PVC may constitute a problem during use in connection with unintentional fires. If other materials support a fire PVC will burn under the formation of e.g. carbon oxides and hydrochloric acid fumes. The soot formed at the fire may contain traces of dioxines, dependent on the fire conditions.

3. Method

For each of the selected compounds, an eco-profile has been made. An eco-profile describes the health and environmental impacts of the material through production of raw material, production, use and waste management. The aim of these eco-profiles is to give information on the potential impacts of the material on health and environment. Thus, an eco-profile is able to identify if there are any problematic elements (" the fingerprint") of each single material.

The chapters in each eco-profile report follow the phases in the life cycle of the material: production of raw materials and polymerization, compounding and processing, use, and waste management.

It should be mentioned explicitly that during production of raw materials and polymerization, the focus has been made on the polymer while the different additives (including the consumption of energy during production of raw materials for the filler) are evaluated during compounding and processing. The evaluation of additives is based on screening for potential health and environmental effects (hazard assessment).

Eco-profiles take into account material and energy inputs and outputs in the form of emissions to land, air, and water. They do not pretend to be a full-scale life cycle assessment methodology but a screening of the potential impact of a particular material on health and environment and can provide the raw data on which LCA studies on products can be based.

The eco-profile reports describe the compounds through of the following phases

For each of the phases a number of environmental elements are discussed:

The procedure and terminology of these reports have been kept as close as possible to the international development, particularly EU-classification of substances and the work related to SETAC (Society of Environmental Toxicology and Chemistry).

The present report is therefore a summary of a larger reporting complex. Four eco-profile reports, one for each of the 3 selected HFFR compounds and one for NKT's PVC no. 5313 have been made.

The results of this assessment are displayed in both a specific matrix, where the focus is on the material, and in a relative matrix where the compounds are compared to PVC no. 5313 (stabilized with calcium-zinc stabilizers and without the use of chlorinated paraffins). In the specific matrix, each element is graded following a three-step scale

In the relative matrix, the 3 selected compounds are compared in each element using a scaling from much worse than PVC to much better than PVC.

4. Assessment of the selected compounds

In 1993, NKT started to market cables stabilized with calcium-zinc stabilizers instead of lead and without the use of chlorinated paraffins. This evaluation is based on this "new" PVC material no. 5313. The results of this assessment are displayed in a specific matrix, as can be seen in the table below.

From a health and environmental point of view, the problematic elements ("the fingerprints") in the life cycle of PVC are primarily in the production process (including the compounding and processing) and waste management. However, PVC may also constitute a problem during use in connection with unintentional fires.

+++ problematic
+ potentially some concern
0 no or only minor concern
? no information

Note
(1) By combustion in fires, PVC may form HCl and dibenzo-p-dioxins.
(2) After having used the cable product, which has an expected lifetime of at least 20 years.

Specific assessment of NKT's PVC no 5313

Production of raw Emissions of VCM (vinyl chloride monomer), EDC (ethylene dichloride)

material & polymerization and dioxines are the most important substances to control in the production of VCM and PVC, due to their potential large emissions and their health effects. Dioxines are very acute toxic (Ahlborg et al., 1988) while VCM and EDC are classified as toxic and carcinogenic (EU and IARC, 1987). Hydrogen chloride is a corrosive colourless gas which is classified as corrosive and it is very irritating for mucous membranes. From an environmental point of view, it is further important to control releases of all chlorinated substances, including dioxines. The degradation of dioxines in soil is minimal, the substance must be considered as having a high bioaccumulation potential and being highly toxic (Christiansen et al. 1990). The average consumption of energy for the production of 1 kg of PVC is about 67 MJ over all the polymerization processes (Bounstad, 1994).

Compounding and processing In the compounding process, raw PVC is mixed with a number of additives. The additives used with NKT's PVC being fillers, plasticizers, and heat stabilizers.

The effects of VCM and hydrogen chloride described under production of raw materials and polymerization are also valid for this phase. However, the exposure is, in this phase, considerable less.

In the work environment, the filler may cause some irritation and may be hazardous as dust but it is not acute toxic. In the external environment, the filler may cause some temporary damage to local plant during production. However, it is not classified as dangerous to the environment.

Compared with most other normally used stabilizers, the stabilizers used in this material are fairly non-toxic in the work environment.

It is also reported to be relative harmless in the terrestrial environment but one of them may cause acute toxicity in the aquatic environment (Merian E., 1991, Friberg L. et al. 1986, Seiler H. & Sigel H., 1988).

From a toxicological and eco-toxicological point of view, the effects of these substances are less problematic than lead which has been used, previously.

The plasticizers might perhaps be of some concern in the work environ-ment during compounding and manufacturing of products. The plasticizers might be carcinogenic to humans and might have a xenoestrogenic effects Møller, S. et al., 1995). The plasticizer does not seem to be acute toxic to aquatic organisms. However, it may exhibit chronic toxicity and may cause long-term adverse effects in the aquatic environment. Due to low biodegradability at low temperatures and in unacclimated systems, the plasticizer may accumulate in sediments and soils in areas where temperatures are relatively low.

Use The material is only of minor concern in normal use. The filler and stabilizer are locked into the PVC matrix but plasticizer loss may occur. However, the plasticizer which is released to the environment is not expected to cause acute toxic effects in neither the aquatic nor the terrestrial environment but since anaerobic degradation is very slow accumulation may occur in low-oxygenated areas in the environment.

PVC does not burn by itself and has a comparatively high self ignition temperature. However, if other materials support a fire PVC will burn under the formation of e.g. carbon oxides and hydrochloric acid fumes. The hydrochloric acid is very irritative to the respiratory system and corrosive to buildings, especially electronic equipment. The soot formed at the fire may contain traces of dioxines, dependent on the fire conditions.

Waste management When deposited on landfill, PVC is degraded very slowly, if at all. PVC plasticizer may leach out of the product (Malme, 1994) and this could be a source to emissions to soil and water.

Largely, all PVC production waste from cable production can be recycled. For the time being, it is questioned whether it is feasible to recycle PVC from old cables. The reason is partly problems with sorting, partly poor material quality in the often very old cables.

By the incineration of PVC, hydrochloric acid is formed. Because of the environmental effects of the acidic fumes the stack gasses are normally neutralized by the use of large amounts of lime (Hjalmar, Thomassen, Højmark, 1990 and Rasmussen, 1995). However, NKT has forwarded a patent application for a precess which will solve this situation.

The residues from the cleaning of stack fumes from incineration of cable waste contain metals and traces of dioxines. It is necessary to deposit those hazardous residues under controlled conditions and with constant collection and treatment of the leachate.

In Denmark, recycling plants with an approved method to treat old cable waste do exist. However, it is expected that incineration of cable insulation with copper, to a certain extent, takes place in open fires in order to recycle the copper. It is not possible to estimate to what extent this is done.

The problematic elements ("the fingerprints") in the life cycle of the HFFR compounds is primarily the production process. This process takes place at an elevated temperature and pressure and there is thus a risk of run-away reaction with a danger of fires and explosions.

The energy consumption in the production of the HFFR compounds will differ according to the quality of the compounds but will in all circumstances be significantly larger than for PVC compound.

+++ problematic
+ potentially some concern
0 no or only minor concern
? not sufficient information, but may be of some concern

Note

(1) It is assumed that HFFR compounds can be recycled, however, the possibility of recycling HFFR has not yet been demonstrated.

Specific assessment of HFFR compounds

Production of raw material The health effects related to the processing of the selected HFFR

& polymerization compounds are often connected to groups of ingredients instead of single compounds. The production processes are to a great extent closed processes. Emissions of aerosols from a number of acids, ketones and aldehydes are the most important substances to control, these have a potential for airway irritation. In the case of long-term exposure there may be a risk of more chronic effects like a decrease in lung function. Work environment effects in the HFFR processing industry is primary respiratory tract effects.

From an environmental point of view, carbon oxides, sulphur oxides, nitrogen oxides and hydrocarbons are important air emissions. Waste water from the polymerization will contain some oil emulsions, hydrocarbons, dissolved organic materials and residues from various process chemicals. These emissions have a high BOD (Biological Oxygen Demand) value and the waste water should be treated before discharge to the recipient.

Compounding and processing In processes involving heating, thermic degradation might occur. The health and environmental effects would be the same as described during production of raw material and polymerization. No serious toxic effects during normal compounding and processing of HFFR compounds are expected. However, the coupling agents might perhaps be of some concern in the work environment during compounding and manufacturing of products.

Use The material is only of minor concern in normal use. The filler and stabilizer are locked into the polymer matrix and no environmental effects are expected. The raw materials are relatively harmless in the external environment. A potential exposure to materials and degradation products is supposed to be so slight that the effects are negligible.

The polymer in these compounds may acts as a fire promoter, however, some of the additives are used as synergistic flame-retardants. If other materials support a fire the HFFR compounds will burn under the formation of e.g. carbon oxides and polycyclic aromatic hydrocarbons. The inorganic additives will be found in the ashes but is not expected to have any toxic effects.

Waste management The exposure to and the effects on the work environment in relation to waste disposal are not known but they are supposed to be negligible. It is questioned for the time being whether it is feasible to recycle HFFR compounds from old cables. The reason is partly problems with sorting, partly poor material quality.

When deposited on landfill HFFR compounds are very slowly degraded, if degraded at all.

HFFR compounds do not give rise to any serious problems in waste incineration. The total combustion of HFFR compounds mainly yields carbon dioxide, water, carbon monoxide, soot, polycyclic aromatic hydrocarbons (PAH), and ashes containing inorganic materials with a relative low toxicity.

5. Conclusion/comparison

The discussion of the substitution of PVC in cables involves a number of relevant issues such as an evaluation of the effects of chlorinated substances, including dioxines. Not least in recent years, the focus has also been on the additives in PVC. The toxicological and eco-toxicological concern applies, in particular, to lead stabilizing agents, phthalate plasticizers and chloroparaffins. These have all been used in cables, however, in 1993, NKT started to market cables stabilized with calcium-zinc stabilizers instead of lead and without the use of chlorinated paraffins. This evaluation and comparison of possible alternatives (the 3 selected HFFR compounds) is based on the "new" NKT PVC compound no. 5313.

The energy consumption is estimated as being significantly larger for HFFR than for PVC. However, the HFFR compounds must be considered as an environmentally friendly alternative to PVC. This judgement is primarily based on the fact that no carcinogenic substances are released during production. Furthermore, there is no need for addition of plasticizers like eg. phthalates normally used in compounds made of PVC in connection with cable production.

The potential risk for accidents might be fewer in the production of HFFR due to the use of chlorine in the PVC production and the possibility of the formation of corrosive compounds in fires. However, because of the high temperature and pressure in the process production of HFFR, it is considered to have the same potential for impact as the production of PVC.

Furthermore, PVC may constitute a problem during use in connection with unintentional fires. If other materials support a fire PVC will burn under the formation of e.g. carbon oxides and hydrochloric acid fumes. The hydrochloric acid is very irritative to the respiratory system and corrosive to buildings, especially electronic equipment. The soot formed at the fire may contain traces of dioxines, dependent on the fire conditions.

HFFR compounds also result in fewer problems in the waste disposal than PVC due to the lower content of problematic additives and the lower chlorine content. Thus, lower amounts of acidic fumes and dioxines are formed by waste incineration.

Thus, the production of HFFR results in the same or in fewer problems in the work environment and external environment than NKT's PVC through the entire life cycle.

+++ potentially much less impact than PVC
+ potentially less impact than PVC
0 approximately the same impact as PVC
- potentially greater impact than PVC
--- potentially much greater impact than PVC

Note
(1) By combustion in fires, PVC may form HCl and dibenzo-p-dioxins.
(2) This evaluation is based on the possibility of recycling HFFR, however, it has not yet been demonstrated.

Relative assessment of HFFR compounds in relation to PVC

Reference

Ahlborg UG. Håkansson H, Wærn F, Hanberg A (1988). Nordisk dioxinbedömning. Miljørapport 1988:7. Nordisk Ministerråd, København.

Boustead I, b. Eco-profiles of the European Polymer Industry. Report 6: Polyvinyl Chloride. Report for APME, April 1994.

Christiansen K, Grove A. Hansen LE, Hoffmann L, Jensen AA, Schmidt A. Environmental assessment of PVC and selected alternative materials. Environmental Project no. 131, The National Agency of Environmental Protection, Copenhagen, 1990. (in Danish and English).

Friberg L, Nordberg GF, Vouk VB. Handbook on the Toxicology of Metals, Volume 1: General Aspects. Elsevier Science Publisher B.V., 1990.

Hjelmar O. Solid residues from flue gas cleaning at municipal solid waste incinerators, Part II. In Danish. Prepared for Danish EPA. Copenhagen 1992.

IARC. IARC monographs on the evaluation of carcinogenic risks to humans. Overall evaluations of carcinogenicity: An updating of IARC monographs volumes 1 to 42. Supplement 7. Lyon: IARC, 1987.

Malme Bernt. Long term behaviour of PVC in landfills. Summary from the seminar at Petrochemicals Division, Norsk Hydro a.s. Norsk Hydro. September 1994.

Merian Ernest et al. Metals and Their Compounds in the Environment. Occurrence, Analysis, and Biological Relevance. VCH Verlagsgesellschaft mbH, 1991.

Rasmussen, Hans Wilhelm. Affaldsforbrænding i forbindelse med PVC-aftalen. Arbejdsrapporten fra Miljøstyrelsen nr. 39, 1995. Copenhagen, Denmark.

Seiler HG, Sigel H. Handbook on Toxicity of Inorganic Compounds. Marcel Dekker, inc., 1988.