Due to legislation around the safe use of nPB (also known as n-propyl bromide or 1-bromopropane), the substance is banned under REACH regulations from 4 July 2020. Any business still using this solvent in its cleaning and degreasing process must find a replacement as soon as possible, except where authorisation to keep using it is granted.

If business are still using nPB, they must take action to ensure that their cleaning processes are compliant. Here are our top tips to help make the switch and to keep employees and businesses safe:

1. Know how the ban affects your cleaning system

The first step is to understand how the ban will affect different types of cleaning systems. Users of ECSA type I (open top) and type II (enclosed) cleaning systems will need to stop using nPB and use an alternative cleaning agent.

nPB can turn acidic, which corrodes the machinery from the inside, so you may need to also repair or even replace your equipment.

2. Get specialist advice from a business you can trust

Taking advice from a cleaning industry specialist will help users understand the implications of nPB replacement. A full audit and survey of existing equipment will be required to make sure any switch of solvents is be viable, effective and safe. We provide guidance through REACH and other regulations to ensure that businesses understand how to remain compliant, whatever their type of cleaning system.

3. Take stock of the alternatives

All current nPB users will need to identify new replacement cleaning chemistries, but caution is advised. Some alternatives which may be suggested are also restricted solvents, such as Perchloroethylene (PERC) or Methylene Chloride (MECL). These substances pose numerous health risks and usage restrictions are set to be put in place, so they are not safe, and they may require replacement soon. Users should be careful not to simply substitute one harmful substance for another.

One family of alternative solvents is fluorinated materials. However, regulations around the use of F-gases (also known as fluorinated gases) have become increasingly stringent over the last few years. There is a limit on how much F-gas can be sold in Europe and the use of F-gases in new equipment is banned where alternatives with a lower Global Warming Potential (GWP) are available.

F-gases have a very high GWP. Global warming is a gradual increase in the overall temperature of the earth’s atmosphere caused by increased levels of carbon dioxide, CFCs, and other pollutants. GWP is used to represent the equivalent of Co2 being released into the atmosphere. So 1kg of Co2 = a GWP of 1. In the case of F-gases, they have a GWP of up to 11,000.

The table below shows the common HFC and HFE’s offered as replacement alternatives. As the table highlights, many of these fall under F-gas regulations and should be avoided.

Common Name

Chemical Name

GWP

Regulatory Issues

nPb

n-Propyl Bromide, 1-Bromopropane, 1BP

<1

SVHC Sunset Date

HFC 365

1,1,1,3,3-PENTAFLUOROBUTANE

890

F-gas Annex I

HFC 4310

1,1,1,2,2,3,4,5,5,5-decafluoropentane

1640

F-gas Annex I

HFE7100

Ethyl Nonaflouroisobutyl ether

320

F-Gas AnnexII

HFE 7200

Ethyl nonafluorobutyl ether

55

F-Gas AnnexII

HFO

Z)-1,1,1,4,4,4-Hexafluoro-2-butene

<2

None

HFO

Methoxytridecafluorohep-tene isomers

<15

None

New generation cleaning agents are worthy of consideration as a replacement. SF80™ by the new generation Opteon™ range from Chemours™, for example, is a drop-in nPB alternative. SF80 is also unique because it is not affected by any F-gas regulations, which allows businesses to make a one-step replacement, saving time and ultimately costs.

4. Assess the true cost of alternatives

The total cost in use of cleaning agents is sometimes overlooked. Price per litre should not be the only factor to consider. Other restricted solvents may have a similar price point to nPB, but this may mask their overall cost in productivity and safety terms.

Restricted solvents, including nPB, continue to be subject to special storage and handling requirements, as well as vapour extraction and compulsory occupational exposure monitoring - all of which are ‘hidden’ costs. A replacement such as SF80 is non-flammable and has a safety exposure limit of 202ppm (ten times better than PERC), which eliminates all these additional costs and can boost productivity through energy savings and faster component drying times.

5. Undertake trials

Businesses should consider trials of replacement chemistries with their particular components and soil types, as well as new cleaning equipment and agents.

At Fraser Technologies, our facility includes free customer trial centres in the London and Edinburgh areas. These allow you to test out alternative chemistries, as well as new equipment if required, before buying. This helps you to make an informed choice into what the best alternative solution is for your specific needs.

What is the process of replacing nPB?

In 2017, we worked with leading Aerospace manufacturer, BAE Systems, to replace the nPB that they were using with a safer solvent.

The challenge

BAE Systems approached us to assess their existing process to see how they could use an alternative solvent which would be safer, at which point we also discussed additional benefits including efficiency and cost saving.

To assess their existing cleaning processes, we arranged a site visit to inspect the Solvac vapour degreasing systems at two of their facilities. We performed a full system inspection to ascertain suitability of the systems for conversion to Opteon™ SF79, a cleaning fluid chosen for its performance, ultra-low global warming potential (GWP), recyclability, reusability, safety, and ease of use. At the time of the change, SF79 was the leading product for this application and while SF80 has since come on to the market as a refined replacement of SF79, both products are safe and suitable alternatives to nPB.

As part of the process, our objectives were to test the equipment for suitability and compatibility for use with SF79®, as well as the general condition of the equipment and any opportunities to reduce solvent usage. The customer found that their solvent usage was very high and they were aware that reductions would improve their environmental impact, as well as save costs.

Before using nPb, both of BAE’s systems were originally supplied for use with Trichloroethylene (Trike) to flush pipework, so they were long narrow tanks specifically suited to this application. They each had a flushing rig and filtration, and originally had Carbon Absorption Deabsorption systems fitted.

The existing Solvac systems used more than 1 tonne of solvent per year, meaning they both required a permit from the local authority for continued use, further increasing costs for the company.

Due to the legislation around the safe use of Trike and nPB, these systems were fitted with over tank canopies and safety interlocks to ensure operators were not exposed to solvent vapours. One of the systems also had a PPM meter fitted, which restricted the front door from opening until the level of solvent had dropped below a specified level. This, as well as additional safety features, protected operators and reduced emissions.

The results

While there were minor issues with the system, these could be addressed and it was determined that Opteon™ SF79® was a suitable replacement. This has now been fully implemented at two of the locations, while the third is currently transitioning to the new product.

Since moving to Opteon™ SF79®, BAE has achieved the cleaning performance they expect, while also significantly reducing their environmental footprint. As SF79® does not have the acidity issues that nPB does, the customer’s usage was significantly reduced simply because fewer clean outs were required. And importantly, it is safe and easy for operators to use.

Speaking about the results of the change to SF79®, the customer’s Engineering & Governance Lead said: “The transition from nPB to SF79® was relatively straightforward and quick, and communication was good throughout. Fraser Technologies also had a much stronger relationship with the manufacturer than we did, which was especially helpful during the process.

“Due to a reduction in manufacturing throughput, we cannot confirm an exact reduction in annual usage, and therefore cost savings and environmental footprint. However, emissions monitoring that we undertook following the introduction of SF79® showed a reduction in volatile organic compounds to atmosphere compared with the previous solvent. The product’s lower GWP will also contribute to reducing the environmental impact of our site operations.

“Overall, changing to SF79® has been a positive experience and it has helped us to achieve our safety, health and environmental objectives.”