Despite our preoccupation with high purity and controlled specifications we have to accept that there are times when such features really are not needed. For example, for laboratory washing, rinsing and in non-demanding industrial applications.

That's where 'technical grade' comes in. But what, exactly, is 'technical grade'? The name of itself doesn't really describe it.

So in the absence of a defined description here are some examples culled from the internet:

• Chemicals that do not have an established standard set for quality and impurity levels or for products where the purity is <90%. Variation in color and physical form is possible
• Also known as 'industrial grade', used for commercial or industrial purposes
• Technical grade chemicals are less pure than reagent grade chemicals, and are usually used in applications where there are no official standards for impurity levels
• Good quality chemical grade used for commercial and industrial purposes
• Contains small amounts of other chemicals, hence slightly impure, for example 'technical-grade sulphuric acid'
• These products come with a limited specification and are intended for non-critical processes
• These products are suitable for non-critical tasks in the laboratory such as rinsing, dissolving or are used as raw materials in production tasks
• A grade suitable for general industrial use

It isn't really clear where the use of term 'technical' originated. The Cambridge English Dictionary whilst giving a number of definitions for 'technical' doesn't help to shed light on this subject:

• relating to the knowledge, machines, or methods used in science and industry
• relating to the knowledge and methods of a particular subject or job
• relating to practical skills and methods that are used in a particular activity

Maybe the first description listed above points to the answer, where the purity is less than 90%, in that the material is 'technically' the nominal chemical but that there's also an appreciable amount of other constituents present. By the way, since ROMIL technical grade tends to have a higher purity of 98-99% should we even be describing it as 'technical grade'?

However, it's all relative. Compared to our ultra- and super- high purity grades, these products are our lowest purity offering and bear the minimal specifications. In other words, these are our base 'technical grade' products even though they may be better specified than similarly described products available elsewhere.