Some chemicals are more detrimental than others.

This week Europe proposed to add seven more chemicals to the list of substances of very high concern (SVHC). The addition of a chemical to the SVHC list enables European regulators to ban the chemical from the market unless it is proven that the risks are adequately controlled, or there is not a feasible substitute and the socio-economic benefits justify the risk. The proposal contains more of the usual suspects such as phthalates, glycol ethers, and a chromate (the “Erin Brockovich chemical”), as well as some potentially difficult to replace chemicals like a widely used reducing agent and a common universal solvent…

The seven substances proposed for listing are briefly described below. The European Chemicals Agency will take comments from interested parties until the 7th of April 2011 before acting to list them as Substances of Very High Concern (SVHC).

2-ethoxyethyl acetate, or 2-EEA
2-EEA is a glycol ether acetate, and joins EGME (2-Methoxyethanol) and EGEE (2-Ethoxyethanol) on the list of glycol ethers of very high concern due to potential harm to reproductive capability and the development of the unborn child. As a consequence of its classification as a reproductive toxin, 2-EEA has not been manufactured in the EU since 1996, and the last known importer discontinued sales in 2002. Confirming that there are no major uses of the chemical continuing in Europe, no company registered for permission to import amounts over 1000 kg (2200 pounds) per year under the comprehensive REACH law.

But several notifications to the new classification and labeling inventory have been made, suggesting that the chemical continues to be placed on the European market in quantities less than 1 ton per company per year. The listing as a substance of very high concern will enable the EU to learn more about and restrict even these minor uses of the chemical.

Strontium chromate
Strontium chromate, a yellow pigment which is also a good corrosion inhibitor, is used mainly in paint primer for aerospace applications, but also used as a coating in buildings and vehicles. It shares the carcinogenic properties of almost all hexavalent chromium compounds (the “Erin Brockovich chemical“). Roughly 15%, or between 900 and 2000 tons, of the estimated 9000ton/year global production of strontium chromate is used in the European Union.

Because it is used almost exclusively as an undercoating, consumers are generally not exposed during the product use part of the lifecycle. However, loss of adhesion and flaking can lead to release of strontium chromate, and handling at the end-of-life is critical to adequately manage the waste. Because of its anti-corrosion power, this chemical is considered critical in applications where surfaces are not accessible for routine maintenance and inspection.

1,2-Benzenedicarboxylic acid, di-C7-11 -branched and linear alkyl esters (DHNUP)
This chemical belongs to the class of plasticizers known as “phthalates”. The listing of this chemical serves mainly to enable the EU to require better reporting of uses of the chemical in Europe, after conflicting information has made it difficult to determine whether the plasticizer continues to be manufactured or imported inside the EU.

It is used mainly in coatings for electrical and communications cables, but also may still be imported in finished goods containing polyvinyl chlorides (PVC) or foam, in sealants and adhesives – especially in the automotive sector, and even in high-end luggage. It was imported into Canada (referenced in the EU report both as a good source of data and as a source of imports into the EU) in quantities between 10,000 and 100,000 tons in 2006; but good substitutes exist, so it is likely that many uses of this chemical, potentially damaging to both fertility and the unborn child, have been discontinued.

This carcinogenic chemical finds wide use in chemical syntheses, which rely on the ability of this powerful reducing agent to force organic chemicals to react. The hydrazine is mostly broken down in this process so that little remains, however the EU report notes that traces may remain in polyurethane resins after polymerization reactions relying on hydrazine. These uses as an intermediate in chemical syntheses are exempt from control under authorization laws, due to the high level of risk management already required in such applications. Therefore, the listing as a SVHC would control other uses such as corrosion inhibition, plating on plastics, and as rocket fuel.

Hydrazine will be difficult to replace where it is used as a corrosion inhibitor in cooling water systems, for example in nuclear and standard power plants or industrial manufacturing applications like steel, or pulp and paper manufacturing. These industries have already moved to control risks by minimizing the concentrations used, and storage quantities. It has largely been replaced in uses for depositing metals on plastics, although the EU report suggests that “pockets of resistance” to substitution still exist. Hydrazine is also used as a propellant for launching space missions. It is stated in the report that at least 15 years of testing are required before a substitute in this use can be accepted. Nonetheless, use as a rocket fuel has dropped significantly since the 1960’s when three-quarters of hydrazine used was in this application.

1-methyl-2-pyrrolidone, also known as NMP
NMP is used mostly by professionals or industrial workers in applications like professional/industrial paint stripping or degreasing, degreasing silicon wafers for the electronics industry, processing of pesticides and petrochemicals. However, consumers may be exposed to the chemical in consumer paint strippers, when used as a penetration enhancer to help pharmaceuticals pass more readily through the skin, and when used as a solvent for the application of slimicides to food-contact packaging. In Switzerland and Sweden, where manufacturers must register chemicals and their product uses, hundreds of products have been registered for consumer use, in concentrations up to 100% NMP.

The classification of the chemical for possibly harming the unborn child in late 2010 has made it illegal to sell the chemical in general consumer goods at concentrations over 0.1%, and its use is banned also in cosmetics which are regulated in a separate category from general consumer goods. The listing as a substance of very high concern will help protect industrial and professional users, but substitution will be very difficult. This universal solvent has a high “loading capacity,” which means that more of a substitute will be needed to do the same work; even the touted water-based systems often rely on some NMP in the solvent fraction.

1,2,3-trichloropropane (1,2,3-TCP)
This chlorinated solvent may cause cancer and damage fertility. This chemical is a by-product of epichlorohydrin manufacture. While literature reports suggest that over 80% of the by-product is incinerated, several manufacturers contacted by the EU report that “much less (<5%)” is incinerated, at least at the installations questioned.

Historically, this chemical figured in such creative uses as production of food and beverages, in soil fumigants, and as a well drilling aid – potentially contaminating drinking water. No information indicates that these uses continue in the EU (and it appears such uses in the US and Canada have also been discontinued). Today, 1,2,3-TCP mainly forms a building block in the manufacture of pesticides, chlorinated solvents, and cross-linking agents. The listing of this substance as SVHC will ensure that uses remain restricted to these building block applications where the substance is highly controlled before being reacted to form other, less hazardous, chemicals.

1,2-Benzenedicarboxylic acid, di-C6-8-branched alkyl esters, C7-rich (DIHP)
OECD data from 2005 indicate that the substance, for which good substitutes are available, was produced globally in quantities between 20,000 and 200,000 tons. It is a phthalate plasticizer used mainly in vinyl flooring and moldings. After its listing as classified for potential to cause harm to the unborn child, use of this in the EU has been largely discontinued. Manufacture has now been discontinued in Europe, was stopped in the US in 2010, and is believed to have stopped in Asia as well. However, recent registrations and notifications for import of the chemical leave some doubt about this, so the listing as an SVHC should clear up the matter.

This week’s proposal also mentions cobalt dichloride, which was identified as an SVHC in 2008. The information on cobalt dichloride is being aligned to note reproductive toxicity as well as carcinogenic and mutagenic potential. This chemical is used almost exclusively in highly controlled industrial settings, as a starting material for making other chemicals, which use up the cobalt dichloride.