Green Packaging: Environmental Issues for PVC (II)

2.3 PVC Industrial Structure and Description

According to recent statistics, it is estimated that there are more than 21,000 companies and more than 530,000 jobs in the total PVC production and conversion industry in Western Europe, with a turnover of more than 7.2 billion euros, which can roughly divide the industry into four groups: PVC polymerization producers, stabilizer producers, Plasticizer producers and PVC converters. 

There are relatively few PVC polymer producers, most of which are located in Europe, the United States, and Japan, and their production capacity in developing countries has also steadily increased. In Western Europe, annual consumption is slightly higher than annual production. Since the early 1990s, imports have been slightly higher than exports. In 1998, net imports were 230,000 tons (Western Europe production was approximately 5.5 million tons). Some processing companies are integrated in the chlorine or petrochemical industry and also produce ethylene chloride and VCM monomers. In 1999, 10 companies produced VCM and PVC, 40 venues and 52 plants in 10 member countries and Norway, employing approximately 1,000 people. 

Seven European companies (22 plants) produce 98% of stabilizers for sale in Europe. They employ approximately 5,000 people and produce 160,000 tons of stabilizers, with a total value of 380 million euros. 

In 1999, 20 companies in Europe produced approximately 1 million tons of plasticizers, the three largest companies accounted for 40% of total production, and the number of manufacturing enterprises was gradually decreasing. Small companies are banned from producing or buying for large companies. This industry is estimated to have approximately 6,500 employees. Production increased by an average of 1.5% per year from 1990 to 1995. Western Europe is a net exporter of plasticizers. The conversion of PVC into final products requires 2-3 different processing procedures, which are basically completed in 21,000 small and medium-sized enterprises. These SMEs are 90% less than 100 employees, and 5% of employees are between 100 and 500. 5 % The company has more than 500 employees.

3Use of additives in PVC

3.1 The scope and type of additives

In order to provide a special range of final products, PVC polymers are mixed with some additives depending on their use. The composition of PVC compounds (resins + additives) varies greatly depending on the amount of additives. When added to polymers as fillers, stabilizers, lubricants, forming agents, colorants and flame retardants, a large number of different types of PVC compounds are used as processed products, plasticizers (mainly o-phthalate) and The use of stabilizers is very high and constitutes a special property of PVC processing over other plastics. All other types of additives are also used in other plastic materials. 

The most important type of additive is a stabilizing agent that requires scientific analysis of its hazardous properties and risks to human health and the environment, in particular the inclusion of heavy metals such as lead, cadmium, and plasticizers such as phthalates. 

3.2 Stabilizers

In order to prevent thermal and photodegradation, stabilizers are added to the PVC polymer. The type of stabilizer used in the final product is based on the technical requirements of the range. 

Lead stabilizers are the most commonly used ones, especially lead sulfide and lead fluoride. In 1998, 112,000 tons of lead stabilizers were used in Europe, including 5,100 tons of lead metal, which accounted for 70% of the total stabilizer consumption. In 1995, Europe consumed 1.6 million tons of lead, lead stabilizers accounted for 3% of the total consumption, and lead stabilizers were mainly used for pipes, sections and cables. 

Cadmium stabilizers are still used as stabilizers by some manufacturers for the production of PVC window frames, and its use is still permitted by EU regulations. In Europe, the use of cadmium has been greatly reduced, from approximately 600 tons per year in 1992 to 100 tons per year in 1997 and 50 tons per year in 1998. 

In 1998, approximately 14,500 tons of mixed metal solids and 16,400 tons of liquid stabilizers were used in Europe. Of these stabilizers, calcium/zinc and bismuth/zinc systems are the most commonly used. 

Organic tin compounds, with a total consumption of 15,000 tons, are approximately 9.3% of European consumption stabilizers. Various types of organotin compounds, in particular mixtures of mono- and diorgano-tin compounds, are used as stabilizers, mostly for particulate packaging films, bottles, tops and inner liners. 

According to EU Directive 67/548/EEC on the amendment of hazardous substances labelling and classification, most lead compounds including PVC are classified as hazardous substances and are harmful to the environment (ecotoxicity), showing cumulative effects, and lead is persistent. In certain organisms can accumulate. 

According to EU Directive 67/548/EEC, most cadmium compounds are harmful to the environment (ecotoxicity), some cadmium compounds are highly harmful, and some compounds are carcinogenic (secondary), cadmium is persistent, some Cadmium compounds accumulate in some organisms. 

The data for organotin compounds used as stabilizers for PVC shows that dioctyltin is toxic to the immune system. This immunotoxicity effect has not been observed for other organotin compounds used as PVC stabilizers, (dimethyltin, dodecyltin, tin phthalate), dioctyltin may present environmental risks to aquatic environment compounds. . 

The relationship between hazards and risks of chemical substances should be separated. Currently, comprehensive risk analysis has not yet been completed for cadmium and lead compounds used as stabilizers for PVC products. In the EU Regulation 793/93 of March 23, 1993 on the evaluation and control of existing material risks, the risk analysis of cadmium and cadmium oxide is nearing completion. For the Lead, the Committee for Toxicity and Ecotoxicity Science and Environment (CSTEE) recently adopted Denmark's opinion on the prohibition of the use of lead in products. At present, CSTEE is evaluating the risk of lead use, especially the research on the impact of lead on the environment and human health should be adopted in mid-2001. 

For most of the heavy metals, cadmium and lead are used in the product and are discharged into the environment in various ways. Most of these heavy metals are distributed in the environment in a dispersed form, namely through industrial activities, petroleum, fertilizer production, and sewage sludge. Lead and cadmium, the two heavy metals are also used in other products, such as in dry batteries and batteries. In addition to its use in batteries, PVC stabilizers also represent one of the main uses of lead. 
(to be continued)