Number

447-EN

Section

General Section

Use

Abstract

Methylene chloride is used as a solvent and cleaning agent in a company producing construction chemicals (polyurethane foam). Methylene chloride is a carcinogen category 2 and the main concern is related to workers exposure during the cleaning process. After testing eight alternatives, the company found a suitable substitute, however, slight changes to the process are needed (i.e. heating, more after-cleaning).

Substituted substances

Alternative Substances

Reliability of information

Evidence of implementation: there is evidence that the solution was implemented and in use at time of publication

Reason substitution

CMR

Hazard Assessment

Substances to be substituted:
Dichlormethane is suspected of causing cancer and genetic defects (H351) according to harmonized classification. In safety data sheet following additional H-phrases are mentioned: H315 (Causes skin irritation), H319 (Causes serious eye irritation) and H336 (May cause drowsiness or dizziness).

Alternative substances:
There is no harmonised classification according to Annex VI of Regulation (EC) No 1272/2008 (CLP Regulation) or entry in the SUBSPORT´s database on hazardous chemicals (SDSC) for the alternative substances.
As the alternative Resin Cleaner PU21 is a VOC, the closed process for cleaning and wearing personal protective equipment is still required. Since the alternative is not carcinogenic, the risk for workers is reduced. Even though 2-ethylhexyl acetate in Resin Cleaner PU21 is a skin irritant (H315), its concentration in the mixture is only up to 5%. While workers are using appropriate personal protective equipment, the risk can be considered marginal.

Regarding environmental hazards: there is a risk air emissions can increase, yet the amounts are marginal.

Description of Substitution

a) Motivation to apply the alternative:
Methylene chloride is carcinogenic and currently under assessment as an endocrine disruptor. Workers come into direct contact with it during the cleaning process, thus workers exposure was the main motivation for considering substitution. Selected alternative mixture Resin Cleaner PU21 is not classified as hazardous to human health.

b) Description of procedure or technology (including pre-/post-processing):
There are 3 main steps during the cleaning process when workers come into direct contact with the cleaning agent - washing of press plate, pouring chemical for wash-ing of parts and washing of parts. Cleaning is carried out one day a week and direct contact of a worker with cleaning agent fumes is approximately 1 h/week (time needed for directly washing/cleaning). Additionally, there is soaking and draining time without human contact (exposure to environment). All wastes are collected and handed over to a waste management company (disposal via incineration).

c) Way of application: washing/cleaning, soaking, draining

d) Risk management measures (technical, organizational and personal):
Workers that come into contact with methylene chloride have to be medically sur-veilled more often compared to other workers, and doctors have been notified regarding their exposure to methylene chloride.

Safety measures of the cleaning process:
? Washing is carried out in a separate washing room with a fume hood (closed process).
? Workers wear protective gloves, protective clothing (long-sleeved work clothes), protective mask, protective eyewear;
? air exchange and exhaust ventilation in work rooms:
- during disassembly - local exhaust ventilation;
- soaking of details - closed vessels;
- washing of details - closed fume cupboard in a separate room;
- intense or longer maintenance works - positive-pressure air line with auxiliary self-contained air supply;
? the efficiency of the exhaust equipment is periodically checked;
? the resistance of the exposed cables and hoses must be checked beforehand as the PU21 dissolves them (the company replaced them with chemical-resistant materials).

e) Advantage or Disadvantage of alternative
Technical requirements: Alternative is aggressive for some hoses and sealings, therefore replacement of solvent-resistant hose materials is needed and adjustment of working conditions necessary to avoid spread of splashes.
Implementation: Main challenge is related to substantially longer clean-ing time that strongly affects the existing efficient working routine. The alternative solvent needs to be heated in order to achieve a similar cleaning effect as MEC (methylene chloride works at room temperature).
Difficulties of cleaning areas on details with limited access (holes, threads etc).
More manual mechanical after-cleaning is needed.
More after-cleaning with acetone needed compared to MEC (evaporates quickly).
Operational expenses: The alternative is more expensive than methylene chloride (approximate price for methylene chloride - 1,1 ?/kg and Resin Cleaner PU21- 4,50 ?/kg).
Possibly investing into parallel spare parts to allow longer cleaning time is needed.

Case/substitution evaluation

A carcinogenic solvent can be efficiently replaced by a mixture of other less toxic solvents. The alternative passes the SUBSPORTplus screening criteria. Other occupational safety measures have to be considered here. It is worth to mention that the solvents DMSO and 2-ethylhexyl acetate have occupational limit values in Germany for safe handling.

State of implementation

Pilot study

Availability ofAlternative

The alternatives are available on the market.

Producer/Provider

Producer: Esti Chem A/S, homepage: www.estichem.com

Type of information supplier

User

Contact

Henkel Balti OÜ

Further information

Factsheet: Substitution of methylene chloride as cleaning agent in a company producing construction chemicals

Date, reviewed

March 1, 2013