Biological Monitoring

Understanding Isocyanate Monitoring

Posted By Stephanie Hancox on 2017-09-05 09:33

Quick Chemistry lesson.... 

Containing Oxygen, Carbon and Nitrogen...Isocyanates are Carbon-based organic substances; Found in many products ranging from glues, installation foams and paints. With a solid safety scheme in place, workers shouldn't inhale Isocyanates however many factors can increase chances of exposure which we will cover within this blog.

Isocyanate monitoring is both simplistic and straightforward with only a collection of urine sample required. This is just one of our biological monitoring services.  Developed by HSL (Health and Safety Laboratory), a urine sample is used due to this being presently the only type of biological monitoring where an accurate understanding of both the amount and type of isocyanates are being absorbed into the body.                                                                                                                                                        

WHY IS THIS? Isocyanates enter the body in one of three ways (Absorbed through the skin due to contact, Inhaled (this can be down to a number of reasons from poor Respiratory Protective equipment, poor safety regulations ect.), and at times even ingested when a worker fails to thoroughly wash their hands after using products containing isocyanates.).                                                                                                                                                      Once the Isocyanates and absorbed. The body immediately breaks down the products of isocyanates into the urine. This is why it is vital, biological monitoring happens within a maximum timeframe of an hour since last possible exposure to isocyanates. 

But its just Asthma? Isn't it?...                                                                                                                             With the winter season getting closer, we changing in temperture and general environment brings on cold like symptoms such as : Persistent Cough, Wheezing, sore and watering eyes, chest tightness, blocked nose and easily becoming breathless. However did you know these are the early signs of isocyanate exposure?

More chemistry based facts...What do different types of Isocyanates break down into?....

                      Isocyanates                                                                            Breakdown Product

2,4 Toluenediisocyanate (TDI) --------- Breaks down to ---------- 2,4 Toluenediamine

2,6 Toluenediisocyanate (TDI) --------- Breaks down to ---------- 2,6 Toluenedimine

Hexamethylenediisocyanate (HDI) ---Breaks down to -----------1,6 Hexamethylendiamine

Isophoronediisocyanate (IPDI) ---------Breaks down to ----------- Isophoronediamine (IPDU(u))

Methylenediphenyl Diisocyanate (MDI) --Breaks down to ---Methylenendianiline (MDA)

What if my employees want to refuse testing? ...

From time to time we do come across workers who prefer to not to go ahead with biological monitoring or Occupational Health assessments for a variety of reasons. And as so they can refuse surveillance through signing a "refusal form". 

Unfortunately, you as the employer have a legal duty of care to fulfil all health and safety regulations to monitor any risk of exposure to ensure that any safety measures put in place are working efficiently. Especially when it is made "necessary" from your most recent COSHH risk assessment. If an employee refuses to take part in the biological monitoring after you have explained the importance to both the company and the individual; You can be in breach of Health and Safety laws. Should the employee refuse after being given all information such as 'only isocyanates will be tested for and nothing else i.e. drugs, pregnancy or STD's', you may wish to move the employee to a different workstation where exposure to isocyanates is greatly reduced. 


What to do about POSITIVE RESULTS...

Once samples are sent off to the laboratory and tested. The results come back with one of three results...           Non-Detected                       Low Exposure               High Exposure     

If the results come back as either Low exposure or High exposure, we recommend a second sample is sent off within a certain time frame recommended by HSL along with....                                                                                                             -Reviewing all safety measures, such as clearance times for invisible mist, which possibly contain                              isocyanates take to clear the work environment.                                                                                                                   -Review all RPE (Respiratory Protective Equipment) and PPE (Personal Protective Equipment). To                              ensure they meet current safety regulations. 

A second urine sample is the most reliable way of confirming that reviewed safety practises have been successful in lowering the possible risk of exposure to isocyanates is as low as possible. 

More information on the types of biological monitoring in which we offer can be found here

Sources of Information: