According to Uwe Falk, Lubrizols global commercial manager, biocides, Water-based lubricants like metalworking fluids and some hydraulic fluids are even more susceptible to microbes because they contain water by design. In a presentation at the UNITI Mineralol Technologie Forum in Stuttgart, Germany, in April, he added, Non-water-based lubricants also might have issues if exposed to humidity. In general, fuel, processing and metalworking fluid biocide additives can be used to both prevent microorganism growth and to shock-treat an outbreak.

In general, there are two ways to decontaminate lubricants and fuels degraded by microorganisms: physico-mechanical and chemical. Preventing problems is definitely better than curing, Falk stated.

To prevent microbial contamination in fuels, regular cleaning of the tanks and draining of the water on the tank bottoms is recommended. Cleaning can be more difficult for non-water based lubricants systems, Falk explained. But in water-based systems like some high water content hydraulics fluids, microbial attack can be prevented only by using biocidal active substances. And water-based metalworking fluids will always need to include biocidal active substances, or the microbes will grow.

Lubrizol testing found that lubricant contamination with microor­ganisms is a continuous process for machines used in outdoor environments. Therefore, higher protection is needed, often by regular addition of tank side biocides.

Regulations Limit Choices

As substances able to control microorganisms, biocides are under great scrutiny by European Union regulators for their harmful impact on humans and environment. In Europe, these substances need to be registered under the Biocidal Products Regulation while in the United States, they are regulated through the Federal Insecticide Fungicide and Rodenticide Act, Falk said. He added that in contrast to REACH (Registration, Evaluation, and Authoriza­tion of Chemicals), there is no volume band for registered substances under the BPR, and all biocides must be authorized before use.

According to the BPR, a product is considered biocidal when it is claimed to be as its intended first use and when is has a biocidal effect when added at a certain level. In other words, the compound has an intended dual use.

Active substances used to produce biocide products need an EU-wide registration, and all targeted applications need to be registered, according to Lubrizol. Registration for ready-to-use products for customers should be done for every EU member country. Falk pointed out that since September 2015, no company can sell biocidal substances if it is not on the European Chemical Agency list of authorized suppliers (Article 95).

In addition, applications need to be registered, depending on the areas of use:

PT2 – Disinfection of surfaces/equipment

PT6 – Can preservation (fuel preservation)

PT11 – Preservation of liquid cooling and processing liquids and lubricants

PT13 – Metalworking fluids and hydraulics

Falk explained that most countries in the EU require separate, national registration of biocide product before any sales can be made. However, the required information, actions and cost can vary greatly from country to country. No notification may be needed for metalworking fluids (PT13). On the other hand, notification plus listing in a national hazardous chemicals inventory may be required. Full dossiers may also be necessary.

After a biocidal substance is authorized, all biocidal products need to be registered within two years in all targeted countries by mutual recognition or by ECHA. Authorization could also be done in a member state of choice, with mutual recognition by all other targeted countries, Falk said. He added that the cost in the first country could be up to 50,000 per product and application, while the mutual recognition fee can be as high as 5,000. Beginning on January 1, 2017, centralized biocidal product registration for each PT application can be processed through ECHA, providing EU-wide authorization, according to Falk.

Lubrizol also found that in addition to a number of fees, the authorities could request numerous additional studies and exposure scenarios. Falk cautioned that high costs and stringent evaluation by the authorities could lead to the disappearance of these products from the market. The last biocidal substance and product is expected to be authorized in 2024, he related.

Lubricants and fuels, as well as all other products threated or those that intentionally incorporate biocides are considered Treated Articles. Only products that are EU approved or under evaluation can be used. After May 1, 2017, treated articles can be imported only if the biocidal substance is on the ECHA Article 95 list. Falk also observed that all Treated Articles have to follow both BPR and CLP labeling requirements when the article claims biocidal properties, or an active carries this claim.

Labeling requirements include a note regarding that the article contains biocide and the biocidal property of the treated article. Also, labels must reveal all active substances and their concentration, handling instructions and precautions based on the biocidal product in the article, Falk noted. The label must also list all relevant use instructions, including safety measurements if needed to protect humans and the environment. They must be visible and easy to read, permanent and in the official language of the country of sale. Labels must be on the package, technical data sheet and letter of guarantee, Falk said.

Authorized biocides typically are identified with highly visible labels, noting that every potential hazard has been analyzed in detail with massive data collection, according to Lubrizol. Handling of biocidal products is, therefore, strictly controlled, resulting in a higher administrative burden. As a result, there is a trend to use dual-use products instead, which have biocidal activity aside from their first use such as pH buffers, corrosion inhibitors, etc., Falk concluded.

While formulations containing dual-use components still comply with the BPR, Falk said, It is risky to call such formulations biocide free. Such a claim indicates that the formulation is less dangerous than formulations containing a biocidal product, while in fact the dual use product is acting in a similar way to a biocide.