Introduction

Most countries have developed a fairly extensive legislation to identify chemical hazards and to control their uses when they can potentially put to risk human health and the environment. The legislation assumes that consumers or members of the general public are more at risk because they tend to be less educated about the hazards of the products they are using (do-it-yourself people also fall in that category). It also assumes that while professional users are potentially more exposed to adhesive ingredients from regular use, they tend to be better trained and therefore more likely to follow the necessary precautions.

CLP picto 230Proper labeling of adhesives and sealants packaging is also a legal requirement, and manufacturers usually go beyond the minimum required to ensure safe use of their products as well as customer satisfaction. For example, the European CLP Regulation (EC) No. 1272 / 2008 on the classification, labelling and packaging of substances and mixtures provides CLP pictogrammes and related codes signification aimed at warning about possible risks and hazards.

For obvious reasons when manufacturers have a choice between two adhesive ingredients that perform equally, they will select the less hazardous and less expensive one. However, if one is more expensive or if its hazard classification is higher, it will be necessary to consider a trade-off. Therefore, the presence of a hazardous ingredient reflected on the label's safety information, or in the product's safety data sheet (not supplied to the consumer, unlike to professional users, but available on the internet), may be necessary either for product performance or for cost reasons.

Regarding adhesives and sealants, several of the best performing are very reactive or contain organic solvents, which are linked to specific hazards. Therefore, their safe use requires a minimum understanding of these hazards and of the precautions to take during use.

Some would argue that the best precaution is to avoid using products containing hazardous ingredients, notably those that are classified as carcinogenic, toxic to reproduction, mutagenic or persistent in the environment. Given the current state of technology, they are likely to be disappointed by the results they will obtain unless the use is not demanding.

Others may also argue that the most environmentally-friendly adhesives or sealants are those derived from nature without much form of chemical transformation. That may be true for some uses, such as Gum Arabic gum for labels, but the overall performance trade-off may work out differently in practice. There are few life cycle analysis studies that would make such comparisons based on factual data.

Fortunately, most of the precautions to be taken when using adhesives and sealants are common sense:

  1. Read carefully before use the information provided by manufacturers on the label
  2. In case of doubt, ask the vendor or contact the manufacturer using the phone number generally provided on the label
  3. Professional users should always read and understand the product's safety data sheet (called Material Safety Data Sheet or MSDS in North America)
  4. Never apply an adhesive to a non-intended use
  5. In particular, adhesives or sealants should never be used in contact with skin or food, or otherwise ingested unless specifically intended for skin contact or approved for food contact (ex. Gum Arabic) or medical applications (ex.: dental adhesives, bra or hosiery self-adhesives, self-adhesive bandage)


General Safety Precautions

 


Fire/explosion

Substitution of chlorinated solvents (which have a low fire hazard) by other organic solvents has increased the risk of fire and/or explosion. To lower the risk (especially with aerosol products):

 


Inhalation Exposure

Organic solvents (acetone, methylated spirits or methanol, white spirit, etc.) are sometimes a necessary adhesive ingredient or are required for prior cleaning, or wiping excess adhesive.
Most solvents used today have a low toxicity but if exposure is prolonged, ventilation is inadequate or if the vapor concentration is high, some people may start getting dizzy or feeling sick especially if the solvent odor is strong.
Stop work immediately and ventilate area.

 


Dermal Exposure

Except if working with small amounts of glue, wearing gloves and protective glasses is necessary because glue cannot be easily removed by wiping or by washing with water.
Any trace of organic solvent based or solventless glue contacting the skin must be wiped off using cloth or cotton wool impregnated with solvent and then washed with soap and water. Applying a skin lotion may be necessary to restore the skin's fatty layer. This site offers tips on how to remove sticky residues using commonly available items such as peanut butter and toothpaste:

http://tipnut.com/25-helpful-items-to-remove-sticky-adhesive-goo/

Accidental contact of glue with the eye (especially glues that react with humidity such as cyanoacrylates and reactive polyurethanes) can be very dangerous and medical attention should be sought immediately.
For occasional use and delicate work latex gloves, or single use polyethylene gloves of the type used for painting jobs, are usually adequate. For heavier work the following compatibility chart should be taken into account (taken from Ansell Chemical Resistance Guide, 7th edition)

 

Glove Type and Common Solvent Use

*Limited service

VG= Very Good

G= Good

F=Fair

P=Poor (not recommended)

Solvent

Neoprene

Natural Latex
or Rubber

Butyl

Nitrile Latex

Acetone

G

VG

VG

P

*Ethyl Acetate

G

F

G

F

Ethanol

(denatured alcohol)

VG

VG

VG

VG

Gasoline/Petrol

(Unleaded)

G

P

F

VG

Hexane

F

P

P

VG

Isopropanol

(isopropyl alcohol)

VG

VG

VG

VG

Lacquer Thinner

G

F

F

P

Methanol

(methyl alcohol,

methylated spirit)

VG

VG

VG

VG

Turpentine

G

F

F

VG

White Spirit

(aliphatic naphtha)

VG

F

F

VG

*Xylene

P

P

P

F

 

 

Environmental Exposure

Unused glues should be given in their original packaging to chemical refuse collection points.

Given the need to lower volatile organic compounds (VOCs) emissions to the atmosphere, water-based or solventless adhesives should be preferred unless required by a specific performance need.